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article
A longitudinal, randomized experimental pilot study to investigate the effects of airborne ultrasound on human mental health, cognition, and brain structure. In: Sci Rep 11 (1), S. 5814. DOI: 10.1038/s41598-021-83527-z.
2021
Ultrasound-(US) emitting sources are highly present in modern human environments (e.g., movement sensors, electric transformers). US affecting humans or even posing a health hazard remains understudied. Hence, ultrasonic (22.4 kHz) vs. sham devices were installed in participants' bedrooms, and active for 28 nights. Somatic and psychiatric symptoms, sound-sensitivity, sleep quality, executive function, and structural MRI were assessed pre-post. Somatization (possible nocebo) and phasic alertness increased significantly in sham, accuracy in a flexibility task decreased significantly in the verum condition (indicating hastier responses). Effects were not sustained after p-level adjustment. Exploratory voxel-based morphometry (VBM) revealed regional grey matter (rGMV) but no regional white matter volume changes in verum (relative to placebo). rGMV increased in bilateral cerebellum VIIb/Crus II and anterior cingulate (BA24). There were rGMV decreases in two bilateral frontal clusters: in the middle frontal gyri/opercular part of inferior frontal gyrus (BA46, 44), and the superior frontal gyri (BA4 ,6, 8). No brain-behavior-links were identified. Given the overall pattern of results, it is suggested that ultrasound may particularly induce regional gray matter decline in frontal areas, however with yet unclear behavioral consequences. Given the localization of clusters, candidate behavioral variables for follow-up investigation are complex motor control/coordination, stress regulation, speech processing, and inhibition tasks.Trial registration: The trial was registered at NIH www.clinicaltrials.gov , trial identifier: NCT03459183, trial name: SonicBrain01, full trial protocol available here: https://clinicaltrials.gov/ct2/show/NCT03459183.
In: Sci Rep 11 (1), S. 5814. DOI: 10.1038/s41598-021-83527-z.
LeonieAscone
ChristophKling
J.Wieczorek
ChristianKoch
SimoneKühn
article
A longitudinal, randomized experimental pilot study to investigate the effects of airborne infrasound on human mental health, cognition, and brain structure. In: Sci Rep 11 (1), S. 3190. DOI: 10.1038/s41598-021-82203-6.
2021
Airborne infrasound (IS; emitted by e.g., large machinery, wind farms) is ubiquitous in technologized environments. Health hazards are controversially discussed at present. This study investigated long-term effects of IS on brain (regional grey matter volume; rGMV) and behavior in humans. Specifically engineered infrasonic (6 Hz, 80-90 dB) vs. sham devices were installed in participants' (N = 38) bedrooms and active for 28 nights. Somatic and psychiatric symptoms, sound-sensitivity, sleep quality, cognitive performance, and structural MRI were assessed pre-post. Null findings emerged for all behavioral variables. Exploratory analyses revealed a trend (p = .083) with individuals exposed to IS reporting more physical weakness at post-test (d = 0.38). Voxel-based morphometry (VBM) revealed no rGMV increases, but there were decreases within clusters in the cerebellum VIIIa (bilateral) and left angular gyrus (BA39) in verum. In conclusion, IS does not affect healthy individuals on a global scale. However, future trials should consider more fine-grained specific effects, combining self-report with physiological assessments, particularly directed at bodily sensations and perception. As no brain-behavior-links could be established, the identified grey matter decline cannot be interpreted in terms of potential harmfulness vs. improvement through IS-exposure. Parameters that may best reflect brain changes as established in the present study include motor function, sensory processing/ bodily- and motor-perceptions, working memory, and higher auditory processing (i.e., language-related tasks), which are hence potential target variables for further research.Airborne infrasound (IS; emitted by e.g., large machinery, wind farms) is ubiquitous in technologized environments. Health hazards are controversially discussed at present. This study investigated long-term effects of IS on brain (regional grey matter volume; rGMV) and behavior in humans. Specifically engineered infrasonic (6 Hz, 80-90 dB) vs. sham devices were installed in participants' (N = 38) bedrooms and active for 28 nights. Somatic and psychiatric symptoms, sound-sensitivity, sleep quality, cognitive performance, and structural MRI were assessed pre-post. Null findings emerged for all behavioral variables. Exploratory analyses revealed a trend (p = .083) with individuals exposed to IS reporting more physical weakness at post-test (d = 0.38). Voxel-based morphometry (VBM) revealed no rGMV increases, but there were decreases within clusters in the cerebellum VIIIa (bilateral) and left angular gyrus (BA39) in verum. In conclusion, IS does not affect healthy individuals on a global scale. However, future trials should consider more fine-grained specific effects, combining self-report with physiological assessments, particularly directed at bodily sensations and perception. As no brain-behavior-links could be established, the identified grey matter decline cannot be interpreted in terms of potential harmfulness vs. improvement through IS-exposure. Parameters that may best reflect brain changes as established in the present study include motor function, sensory processing/ bodily- and motor-perceptions, working memory, and higher auditory processing (i.e., language-related tasks), which are hence potential target variables for further research.
In: Sci Rep 11 (1), S. 3190. DOI: 10.1038/s41598-021-82203-6.
LeonieAscone
ChristophKling
ChristianKoch
SimoneKühn
J.Wieczorek
A psychoacoustical study to investigate the perceived unpleasantness of infrasound combined with audio-frequency sound.
Acta Acust. 4 (5), S. 20.
2020
At many immission sites of infrasound (frequency f < 20 Hz), humans are exposed to a mixture of infrasound and sound in the common audio-frequency range (audio sound, 20 Hz < f < 20 kHz). Therefore, the purpose of this study was to examine the auditory perception of infrasound and audio sound not only in isolation but also in combination. This laboratory study aims to investigate the perceived unpleasantness of infrasound (sinusoid at 12 Hz) and audio sound (sinusoid at 1000 Hz, pink-noise 250–4000 Hz), presented alone or in combination with each other. A pairwise comparison task and a rating task using a numerical scale were conducted with 19 normal hearing listeners. In addition, individual detection thresholds were determined for the infrasound stimulus. Combinations of infrasound and audio sound were rated as equally or more unpleasant than either sound presented alone. Inter-individual differences in unpleasantness ratings using the numerical scale were particularly high for stimuli containing infrasound. This can only in part be related to the large variability in infrasound thresholds. These findings suggest that simultaneous exposure to infrasound and audio sound can increase the perceived unpleasantness when both are presented at a sufficient level above the detection threshold.
DOI: 10.1051/aacus/2020019.
ElisaBurke
StefanUppenkamp
ChristianKoch
article
A new approach to hearing assessment, A guidance document for researchers, calibration service providers and audiometric clinicians
2020
An ear simulator user guide targeting stakeholders from health policy, clinical audiologists, calibration service providers and equipment manufacturers, has been prepared, covering all of the EMPIR EARSII (15HLT03) research findings to be disseminated. It also contains guidance for using and applying the new ear simulator family including issues for further development of the methodology.
The research covered many measurement-related aspects of hearing assessment, that have an impact across a wide range of stakeholders from health service policy makers, and hearing assessment practitioners, to instrumentation manufacturers and calibration service providers. This guidance document has been produced to enable the research findings to be disseminated effectively, key achievements to be summarised and recommendations for further research to be made.
The document covers the initial rationale for the project and from the metrology perspective, the improvements in calibration and traceability aimed for. However, it also points to the expected impact on the wider audiometric community, including enhanced service quality for clinicians, new technical drivers for manufacturers of instrumentation, and most importantly greater assurances for patients and their families.
There is a description of the proposed new approach to hearing assessment that flows from having ear simulators covering different age points for the first time, and consideration of the continuity issues that may arise from introducing such significant changes. It covers innovations in calibration and in specifying the level of short-duration test stimuli that calibration service providers and the standardisation community alike can adopt and build upon. Importantly it also defines the scope of further audiological research needed to help establish the new ear simulator specifications and see them become embodied in international standards and gain acceptance.
https://oar.ptb.de/resources/show/10.7795/EMPIR.15HLT03.RE.20201020
Datei herunterladen (application/pdf) 1.22 MB (1276880 Bytes)
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Ear simulators ; Objective audiometry ; Audiological equipment ; Hearing assessmen
RichardBarham
ErlingSandermann Olsen
SalvadorBarrera Figueroa
EnverSadikoğlu
ChristianHof
ThomasFedtke
ChristianKoch
article
Datasets of high spatial resolution scans of the airborne ultrasound field at the front, back and left side of an ultrasonic welding machine
2020
This dataset contains measuring data which are the result of investigations of the airborne ultrasound field of an ultrasonic welding machine. These investigations have been conducted within the scope of the EMPIR project 15HLT03: “Ears II - Metrology for modern hearing assessment and protecting public health from emerging noise sources”. In the context of “Ears II”, they served gaining knowledge for occupational safety and health. Here, the aim was to investigate the structure of the airborne ultrasound field at ultrasound related workplaces. Therefore, a reference workstation was set up in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB). The airborne ultrasound field of a typical industrial source of airborne ultrasound (an ultrasonic welding machine) was measured with a scanning microphone system with a high spatial resolution.
https://zenodo.org/record/3550527#.X3MNoWgzZaQ
DOI: 10.5281/zenodo.3550527
R.Schöneweiß
ChristophKling
ChristianKoch
article
A laboratory study for occupational safety and health on the structure of airborne ultrasound fields
Acta Acust. Volume 4, Number 4
2020
While exposure to airborne ultrasound is increasing in occupational contexts and in public and private spaces, existing demand for reliable and traceable determination of exposure to sound with frequencies above 16 kHz cannot currently be satisfied due to a lack of adequate measurement devices and procedures adapted to the specifics of airborne ultrasound. So that this study may serve as a first step for the development of a novel measurement procedure, its aim is to create a comprehensive database of the structures of airborne ultrasound fields present in occupational contexts. Based on this, the limitations of measurement procedures commonly used in the audible frequency range are clarified and the structural characteristics of airborne ultrasound fields investigated. This paper presents a laboratory study of the structure of the airborne ultrasound field of an ultrasonic welding machine, which can be considered a representative occupational source of airborne ultrasound. For this study, the technical and procedural requirements of a measuring system are derived and used to set up and calibrate a measuring system for three-dimensional, high spatial resolution scans of sound pressure levels in the laboratory. The measurement results reveal complex, extensive and very fine-structured interference patterns, some of which have sound pressure levels of up to 138 dB (re 20 μPa).
https://doi.org/10.1051/aacus/2020013
Airborne ultrasound / Measuring system / Spatial scanning of sound pressure levels / Sound field mapping / Ultrasonic noise
R.Schöneweiß
ChristophKling
ChristianKoch
article
Detection Thresholds for Combined Infrasound and Audio-Frequency Stimuli
Acta Acustica united with Acustica, S. Hirzel Verlag, 2019 , 105 , 1173-1182
2020
This study investigated whether the presence of audio sound (20 Hz < frequency f < 20 kHz) influences the detection threshold for infrasound (f < 20 Hz), and, vice versa, whether the presence of infrasound influences the detection threshold for audio sound. Monaural detection thresholds of thirteen otologically normal listeners were repeatedly determined for infrasound stimuli (sinusoids at 5 Hz and at 12 Hz) and for audio sound stimuli (sinusoids and bandlimited pink noise), separately and in presence of the respective other sound type. The measurements were performed with an adaptive 1-up-2-down 3-alternative forced-choice (3-AFC) procedure. Threshold levels for infrasound stimuli were not affected by audio sound at +5 dB sensation level (SL), but they were significantly increased by the presence of some of the audio sound stimuli presented at +50 dB SL. For example, thresholds for the detection of infrasound increased on average by around 5 dB when simultaneously presented with a pink-noise stimulus (frequency range: 250 Hz– 4000 Hz). On the other hand, the presence of infrasound with levels up to +10 dB SL did not cause any significant change in the detection thresholds for audio sound. This could be an indication that infrasound might even be more annoying in a quiet environment.
https://doi.org/10.3813/AAA.919394
ElisaBurke
JohannesHensel
ThomasFedtke
StefanUppenkamp
ChristianKoch
article
Activation in human auditory cortex in relation to the loudness and unpleasantness of low-frequency and infrasound stimuli
PLoS ONE 15(2): e0229088
2020
Low frequency noise (LFS) and infrasound (IS) are controversially discussed as potential causes of annoyance and distress experienced by many people. However, the perception mechanisms for IS in the human auditory system are not completely understood yet. In the present study, sinusoids at 32 Hz (at the lower limit of melodic pitch for tonal stimulation), as well as 8 Hz (IS range) were presented to a group of 20 normal hearing subjects, using monaural stimulation via a loudspeaker sound source coupled to the ear canal by a long silicone rubber tube. Each participant attended two experimental sessions. In the first session, participants performed a categorical loudness scaling procedure as well as an unpleasantness rating task in a sound booth. In the second session, the loudness scaling procedure was repeated while brain activation was measured using functional magnetic resonance imaging (fMRI). Subsequently, activation data were collected for the respective stimuli presented at fixed levels adjusted to the individual loudness judgments. Silent trials were included as a baseline condition. Our results indicate that the brain regions involved in processing LFS and IS are similar to those for sounds in the typical audio frequency range, i.e., mainly primary and secondary auditory cortex (AC). In spite of large variation across listeners with respect to judgments of loudness and unpleasantness, neural correlates of these interindividual differences could not yet be identified. Still, for individual listeners, fMRI activation in the AC was more closely related to individual perception than to the physical stimulus level. Published: February 21, 2020https://doi.org/10.1371/journal.pone.0229088
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0229088
Citation: Behler O, Uppenkamp S (2020) Activation in human auditory cortex in relation to the loudness and unpleasantness of low-frequency and infrasound stimuli. PLoS ONE 15(2): e0229088. https://doi.org/10.1371/journal.pone.0229088
1
ChristianBehler
StefanUppenkamp
article
Datasets of high spatial resolution scans of the airborne ultrasound field of an ultrasonic welding machine either with or without an artificial head at a worker’s sedentary position
2019
This dataset contains measuring data which are the result of investigations of the influence of a person on an airborne ultrasound field. These investigations have been conducted within the scope of the EMPIR project 15HLT03: “Ears II - Metrology for modern hearing assessment and protecting public health from emerging noise sources”. In the context of “Ears II”, they served gaining knowledge for occupational safety and health. Here, the aim was to investigate the influence of a worker on the airborne ultrasound field at his or her workplace. Therefore, a reference workstation was set up in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB). The airborne ultrasound field of a typical industrial source of airborne ultrasound (an ultrasonic welding machine) was measured with a scanning microphone system with a high spatial resolution. 2 measurements have been performed with an artificial head in front of the ultrasonic welding machine at a worker’s sedentary position. Those 2 measurements have been performed at a vertical surface with dimensions 24 cm x 27 cm (width x height) in the same plane as the ear canal of the artificial head, one measurement each at the left and the right side of the artificial head. For comparison with an uninfluenced sound field, these measurements have been repeated at the same surfaces without the artificial head in front of the ultrasonic welding machine. The measuring data is the discrete Fourier transform of the squared signal voltage re 1 V^2 represented in the frequency domain, converted by fast Fourier transform, in the frequency range 0 – 100 kHz with a resolution bandwidth of 15.625 Hz. The data can be converted to sound pressure levels (SPL) using the given calibration values.
DOI: 10.7795/720.20190606
https://oar.ptb.de/resources/show/10.7795/720.20190606
R.Schöneweiß
ChristophKling
ChristianKoch
article
Deductive development and validation of a questionnaire to assess sensitivity to very low and very high frequency sounds: SISUS-Q (Sensitivity to Infra-Sound and Ultra-Sound Questionnaire).
Noise & health 21 (101), S. 173–182
2019
Auditory research and complaints about environmental noise indicate that there exists a significant, small subgroup within the population which is sensitive towards infra- and low-frequency or ultra- and high-frequency sounds (ILF/UHF). This paper reports on the development, factorization and validation of measures of sensitivity towards frequencies outside the common hearing range. Design: A multinational, cross-sectional survey study was run. Principal component analyses and exploratory factor analyses were conducted in a sample of 267 Europeans (from the UK, Slovenia, and Germany). Results: The factor analyses suggested that ILF versus UHF sensitivity constitute different factors, each characterized by sensory perception, stress-responsivity, and behavioral avoidance. A third factor comprising beliefs of dangerousness of ILF and UHF emerged. The factors explained 72% of the variance. The factor-solution was replicated separately for the English (n = 98) and German (n = 169) versions of the questionnaire (Slovenians and UK residents filled out the English version). Acceptable to excellent reliability was found. ILF and UHF sensitivity were moderately related to noise sensitivity in the normal hearing range, suggesting the new measures are not redundant. Correlations with psychiatric and somatic symptoms were small to moderate. ILF sensitivity correlated with neuroticism (small effect) and daytime sleepiness (moderate effect). ILF and UHF sensitivity were related to agreeableness (small effects). Overall, the novel ILF and UHF sensitivity scales seems to provide a solid tool for conducting further research on the role of sensitivity concerning adverse effects of ILF and UHF sound (e.g. health outcomes, annoyance ratings). The questionnaire consortium recommends using the new scales in combination with established measures of normal hearing range sensitivity.
DOI: 10.4103/nah.NAH_46_19
http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2019;volume=21;issue=101;spage=173;epage=182;aulast=Ascone;type=0
LeonieAscone
StefanUppenkamp
ChristianBehler
B.Lineton
ElisaBurke
ChristianKoch
SimoneKühn
GregorGeršak
article
Sound Source System for Investigating the Auditory Perception of Infrasound Accompanied by Audio Sound
Acta Acustica united with Acustica, S. Hirzel Verlag, 2019 , 105 , 869-874
2019
To gather more basic knowledge about both infrasound-perception mechanisms and the annoyance caused by infrasound, it is important to investigate the influence of the interaction between infrasound and sound at frequencies inside the common audio frequency range (audio sound) on the auditory perception. This paper gives a detailed description of a newly developed sound source system allowing simultaneous monaural stimulation of listeners with infrasound and audio-sound stimuli in psychoacoustic experiments. The sound source system covers a frequency range between 4 Hz and 6000 Hz. It can generate infrasound stimuli and audio-sound stimuli up to at least 123 dB SPL and 80 dB SPL, respectively, with inaudible harmonic distortions. Likewise, during simultaneous generation of high-level infrasound and audio sound, residual unwanted modulation frequencies remain imperceptible, owing to special design features. It can be concluded that the sound source system is suitable for investigating the auditory perception of infrasound accompanied by audio sound.
https://doi.org/10.3813/AAA.919366
ElisaBurke
JohannesHensel
article
Equivalent hearing threshold levels for the RadioEar IP30 insert earphone and short-term stimuli: comparison of peak-equivalent and RMS-based measures
International Journal of Audiology, Taylor & Francis, 2019 , 0 , 1-5
2019
Objective: To determine equivalent threshold sound pressure levels (ETSPL) for the RadioEar IP30 insert earphone for standardised short-term stimuli: IEC 60645-3 reference clicks and tonebursts in the frequency range from 250 Hz to 6 kHz, using the standardised peak-equivalent ETSPL procedure (peETSPL) and a new proposal based on the unweighted equivalent continuous sound pressure level LZeq. of the periodically repeated short-term stimuli (LZeqETSPL).
Design: Determination of peETSPL and LZeqETSPL hearing threshold levels with otologically normal test subjects under the conditions given in ISO 389-9 using the standardised occluded-ear simulator according to IEC 60318-4.
Study sample: The study was based on tests with 25 subjects.
Results: The peETSPLs for the RadioEar IP30 insert earphone were compared with the respective reference threshold levels of the insert earphone ER-3A as standardised in the ISO 389 standards series. The LZeqETSPL approach was tested by estimating the LZeqETSPLs from the peRETSPLs and comparing the estimate with the direct results.
Conclusions: Equivalent hearing threshold levels for standardised short-term stimuli for the RadioEar IP30 insert earphone were determined according to ISO 389-9 and given as both peETPSL and LZeqETSPL. The RMS-based LZeqETSPL approach turned out to be well applicable for the RadioEar IP30 insert earphone.
https://doi.org/10.1080/14992027.2019.1682690
ThomasFedtke
Marion U.Bug
article
Brain’s Frequency Following Responses to Low-Frequency and Infrasound
Archives of Acoustics Vol. 45, No. 2, pp. 313–319 (2020)
2019
Complaints and awareness about environmental low-frequency (LF) noise and infrasound (IS) have
increased in recent years, but knowledge about perceptual mechanisms is limited. To evaluate the use of
the brain’s frequency-following response (FFR) as an objective correlate of individual sensitivity to IS and
LF, we recorded the FFR to monaurally presented IS (11 Hz) and LF (38 Hz) tones over a 30-phon range
for 11 subjects. It was found that 11-Hz FFRs were often significant already at 0 phon, steeply grew to
20 phon, and saturated above. In contrast, the 38-Hz FFR growth was relatively shallow and continued
to 60 phon. Furthermore, at the same loudness level (30 phon), the 11-Hz FFR strength was significantly
larger (4.5 dB) than for 38 Hz, possibly reflecting a higher phase synchronization across the auditory
pathway. Overall, unexpected inter-individual variability as well as qualitative differences between the
measured FFR growth functions and typical loudness growth make interpretation of the FFR as objective
correlate of IS and LF sensitivity difficult.
DOI: 10.24425/aoa.2020.133151
1
TorstenMarquardt
CarlosJurado
article
On the Effectiveness of airborne infrasound in eliciting vestibular-evoked myogenic responses
Journal of Low Frequency Noise, Vibration and Active Control 39 (1), 3 -16. DOI: 10.1177/1461348419833868.
2019
The use of airborne infrasound and other stimuli to elicit (cervical) vestibular-evoked myogenic potentials (cVEMPs) was studied to address the common proposition that infrasound may efficiently stimulate the vestibular system, an effect which may underlie the so-called wind-turbine syndrome. cVEMPs were measured for both ears of 15 normal-hearing subjects using three types of airborne sound stimulation: (1) 500-Hz tone bursts (transient); (2) 500-Hz sinusoidally amplitude-modulated tones at a 40-Hz rate (SAM); and (3) low-frequency and infrasound pure tones (LF/IS). The two former stimulation types served as control and allowed a systematic comparison with (3). It was found that SAM stimulation is effective and appears to be comparable to transient stimulation, as was previously observed in a yet small number of studies. Although the vestibular system is reported to be highly sensitive to low-frequency mechanical vibration, airborne LF/IS stimulation at ∼80–90-phon loudness levels did not elicit significant saccular vestibular responses.
https://doi.org/10.1177/1461348419833868
CarlosJurado
TorstenMarquardt
article
Does airborne ultrasound lead to activation of the auditory cortex?
Biomedical Engineering/Biomedizinische Technik, De Gruyter, 2019 , 64 , 481-493
2019
As airborne ultrasound can be found in many technical applications and everyday situations, the question as to whether sounds at these frequencies can be heard by human beings or whether they present a risk to their hearing system is of great practical relevance. To objectively study these issues, the monaural hearing threshold in the frequency range from 14 to 24 kHz was determined for 26 test subjects between 19 and 33 years of age using pure tone audiometry. The hearing threshold values increased strongly with increasing frequency up to around 21 kHz, followed by a range with a smaller slope toward 24 kHz. The number of subjects who could respond positively to the threshold measurements decreased dramatically above 21 kHz. Brain activation was then measured by means of magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) and with acoustic stimuli at the same frequencies, with sound pressure levels (SPLs) above and below the individual threshold. No auditory cortex activation was found for levels below the threshold. Although test subjects reported audible sounds above the threshold, no brain activity was identified in the above-threshold case under current experimental conditions except at the highest sensation level, which was presented at the lowest test frequency.
https://doi.org/10.1515/bmt-2018-0048
1
RobertKühler
SimoneKühn
TilmannSander-Thömmes
BerndIttermann
AlbrechtIhlenfeld
Rü.Brühl
JohannesHensel
MartinBauer
MarkusWeichenberger
ChristianKoch
article
Individualized magnetoencephalography using optically pumped magnetometers with an anatomy derived sensor holder
Biomedical Engineering Biomedical Technics, 63 , 63 , S240
2018
Cardiovascular diseases are the leading cause of death worldwide. Early detection of abnormal vascular morphologies
like aneurysms in the abdominal (abdominal aortic aneurysm, AAA) or thoracic aorta (thoracic aortic aneurysm, TAA)
are essential to prevent fatal events. The aim of this study is the development of a patient-specific simulation model to
obtain statistical information about normal/abnormal pressure-flow conditions to improve the basic understanding
and methods for the early detection of diseases. For this purpose, the numerical cardiovascular modeling tool SISCA
was used, to generate a series of simulations by Monte-Carlo parameter variation. The considered variational scenario
was built upon a control group of normal patients, deriving two pathological conditions for AAA and TAA with different
severity and location. Therefore, the nominal diameters were enlarged between 200 % and 500 %, while the length
of the aneurisms were modified within a range of 30 and 90 mm. Within each statistical set the convergence was tested
by the bootstap method ensuring that within a set of 3500 runs a 2 % deviation error of the mean value of the blood
pressure was obtained compared to a set of 10.000 runs.The parameter variation method allows the generation of disease
specific data in the context of physiological/clinical findings and consequently the disease specific quantification
of signal uncertainties and variances.
DOI:10.1515/bmt-2018-6045
AnnaJodko-Wladziska
TaoxiYang
RüdigerBrühl
PatriciaCotic Smole
LutzTrahms
VojkoJazbinšek
Tilmann H.Sander
article
Amplitude Modulation May Be Confused with Infrasound
Acta Acustica united with Acustica, S. Hirzel Verlag, 2018 , 104 , 825-829
2018
Environmental infrasound is usually accompanied by low-frequency (LF) sounds. Considering that inner hair cell transduction equals half-wave rectification, activity of low-frequency auditory nerve fibres may be indistinguishable whether elicited by LF sound that is amplitude-modulated at an infrasonic rate, or LF sound that is superimposed onto infrasound that "biases" the basilar membrane position. We tested whether listeners are able to distinguish a 63-Hz carrier tone, amplitude modulated at 8 Hz, from a 63-Hz pure tone that was perceptually loudness-modulated by an 8-Hz biasing tone. Using a maximum-likelihood procedure, 12 participants first adjusted the intensity of the 8-Hz tone so that the perceived modulation of the pure tone matched a reference amplitude-modulated tone. Both stimuli types were then presented in random order, and participants had to identify presentations which contained the infrasound tone. About half the participants performed close to chance. The best had 81% correct. Experiments with a 125-Hz carrier tone gave similar results. Although performance may improve in a 2-interval discrimination task, this would not be representative of real listening conditions. Results suggest that slowly amplitude-modulated LF sounds may underlie complaints about environmental infrasound, where measured infrasound levels are well below sensation threshold.
https://doi.org/10.3813/AAA.919232
© 2018 The Author(s). Published by S. Hirzel Verlag · EAA. This is an open access article under the terms of the Creative Commons Attribution (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).
TorstenMarquardt
CarlosJurado
article
A novel measurement technique for the assessment of industrial ultrasonic noise
Occupational and Environmental Medicine 2018;75:A525.
2018
Introduction Although the possible negative health effects of exposure to high energetic ultrasonic noise were discussed since the adoption of the technology in the 1940s, no major research was conducted on this topic since the late 20th century and it only regained focus approximately 10 years ago. Nevertheless, guideline values and limits have been established for the exposure to ultrasonic noise in several countries. The Ears II project was brought to life under the umbrella of the EU’s EMPIR, to investigate the human perception of non-audible sound and its possible effects on human health. In this context the Institute for Occupational Safety and Health and the National Metrology Institute of Germany developed a measurement technique for assessing industrial ultrasonic noise.
Methods Existing measurement techniques for audible sound were evaluated for their applicability to measuring ultrasound. Through evaluation of existing data a reference workplace was developed for laboratory measurements. These comprised simulated practical measurements and high spatial resolution scans of the sound field of an ultrasonic welding machine. Finally, a method was developed and tested in field measurements.
Results The existing standards for assessment of the exposure to noise negate the applicability to ultrasonic noise. The same is true for the standards covering technical requirements for sound level metres. A novel technique was successfully developed and field measurements were carried out.
Conclusion The existing standards are mostly insufficient for the assessment of the exposure to ultrasonic noise. Either applicability to ultrasound is ruled out a priori or the methods or technical specifications are insufficient for the measurement of ultrasound, because the frequency range of interest is not covered, for example.
Based on an existing guideline a novel method was developed, which will, if necessary, be adapted to practical needs after examination of its practical applicability by evaluation of the field tests.
http://dx.doi.org/10.1136/oemed-2018-ICOHabstracts.1487
1
ChristianUllisch-Nelken
AndreaWolff
R.Schöneweiß
ChristophKling
article
Ultrasound in air—Guidelines, applications, public exposures, and claims of attacks in Cuba and China
The Journal of the Acoustical Society of America 144, 2473
2018
This editorial introduces a Special Issue of the Journal of the Acoustical Society of America, on “Ultrasound in Air.” In this Special Issue, one paper covers ways of categorizing the ultrasonic regimes, and three papers cover human effects. One of those three, plus five others, constitute the six papers that report on the measured outputs of commercial devices. Two cover calibration, and the final three papers cover novel applications. This editorial outlines the context in which these papers provide individual studies, including the development of technology and guidelines for safe exposure, and ending with an analysis of what is currently known about claims of sonic attacks on embassy staff in Cuba and China.
The Journal of the Acoustical Society of America 144, 2473 (2018); https://doi.org/10.1121/1.5063351
1
T. G.Leighton
article
Public exposure to ultrasound and very high-frequency sound in air
The Journal of the Acoustical Society of America 144, 2554–2564
2018
Recent work showing the presence of a new generation of ultrasound (US) sources in public places
has reopened the debate about whether there are adverse effects of US on humans, and has identified weaknesses in standards and exposure guidelines. Systems that rely on very high-frequency
sound (VHFS) and US include public-address voice-alarm (PAVA) systems (whose operational status is often monitored using tones at 20 kHz) and pest deterrents. In this study, sound pressure levels (SPLs) produced by 16 sources that were either publically available or installed in busy public
spaces were measured. These sources were identified through a citizen science project, wherein
members of the public were asked to provide smartphone recordings of VHFS/US sources. With
measurements made in realistic listening positions, pest deterrents were found that produced levels
of up to 100 dB SPL at 20 kHz, and a hand dryer was found to produce 84 dB SPL at 40 kHz.
PAVA systems were found to emit lower levels of up to 76 dB SPL at 20 kHz. Pest deterrents
measured breach recommended safe listening limits for public exposure for people who are nearby
even for relatively short periods. VC 2018 Acoustical Society of America.
https://doi.org/10.1121/1.5063817
1
M.D.Fletcher
S.D:Lloyd Jones
P.R.White
C.N.Dolder
B.Lineton
T. G.Leighton
article
Measurements of ultrasonic deterrents and an acoustically
branded hairdryer: Ambiguities in guideline compliance
The Journal of the Acoustical Society of America 144, 2565 (2018)
2018
Acoustic radiation from three commercial pest deterrents and two hair dryers were measured in an
anechoic chamber. The deterrents were chosen because the frequency range at which they emit the
most energy is either in the very high-frequency sound band (11.2–17.8 kHz) or the ultrasound
band (greater than 17.8 kHz). These are sources that may be heard by a subset of the general population, with the young typically having better high frequency sensitivity. A hairdryer reported to
increase the frequency of the motor noise above the audible hearing range was compared with a
standard hairdryer. The outputs of the deterrents are compared against six international regulations
and guidelines for audible and ultrasound exposure. Multiple ambiguities in the application of these
guidelines are discussed. These ambiguities could lead to a device being considered as in compliance despite unconventionally high levels. Even if a device measured here meets a guideline, actual
exposures can exceed those taken here and may therefore breach guidelines if the listener is closer
to the device or reflections increase the exposure level. VC 2018 Acoustical Society of America.
https://doi.org/10.1121/1.5064279
1
C.N.Dolder
M.D.Fletcher
S.D:Lloyd Jones
B.Lineton
S.R.Dennison
M.Symmonds
P.R.White
T. G.Leighton
article
Frequency bands for ultrasound, suitable for the consideration of its health effects
The Journal of the Acoustical Society of America 144, 2490 (2018)
2018
It is proposed that the ultrasound frequency spectrum should be divided into three bands in order to facilitate a more rational assessment of its health effects. Whilst statement of the frequencies at the borders of these bands facilitates their definition, it is recognized that these observables vary continuously with frequency and consequently these border frequencies should not be used to rule out the possibility of a given effect occurring. The lowest band, US(A), lies between 17.8 and 500 kHz. In this band acoustic cavitation and its associated forces form the dominant process resulting in biological effects in liquids and soft tissues, whereas health effects from airborne ultrasound have been reported but are far less researched. In the middle band, US(B), between 500 kHz and 100 MHz, temperature rise in tissues becomes the most important biological effect of exposure. The highest band, US(C), covers frequencies above 100 MHz, for which the radiation force becomes an increasingly important biophysical mechanism. A justification for the selection of 17.8 kHz in preference to any other threshold for the lower frequency limit for ultrasound is given.
1
F.Duck
T. G.Leighton
article
Effects of very high-frequency sound and ultrasound on humans. Part II: A double-blind randomized provocation study of inaudible 20-kHz ultrasound
The Journal of the Acoustical Society of America 144(4), 2511-2520
2018
Various adverse symptoms resulting from exposure to very high-frequency sound (VHFS) and
ultrasound (US) have previously been reported. This study aimed to establish whether these symptoms are experienced under controlled laboratory conditions and are specific to VHFS/US. To do
this, participants were exposed to VHFS/US (at frequencies between 13.5 and 20 kHz and sound
pressure levels between 82 and 92 dB) and to a 1 kHz reference stimulus, both at 25 dB above their
hearing threshold. The VHFS/US and reference stimuli were presented 4 times, each time for
3 min, during which participants performed a sustained attention task, rated their symptom severity,
and had their galvanic skin response (GSR) measured to assess their level of anxiety. Prior to exposure, participants were assigned either to a symptomatic or an asymptomatic group, based on their
prior history of symptoms that they attributed to VHFS/US. In both groups, overall discomfort ratings were higher in the VHFS/US condition than the reference condition. In the symptomatic group
only, difficulty concentrating and annoyance were also rated higher in the VHFS/US than the reference condition. No difference between the two stimulus conditions was seen in performance on the
attention task or on average GSRs for either group. VC 2018 Acoustical Society of America.
https://doi.org/10.1121/1.5063819
1
M.D.Fletcher
S.D:Lloyd Jones
B.Lineton
P.R.White
C.N.Dolder
T. G.Leighton
B.Lineton
inbook
Analysis of the Noise Exposure and the Distribution of Machine Types at Ultrasound Related Industrial Workplaces in Germany
Acta Acustica Untied with Acustica, Issue 104/5, p.733-736
2018
Since its introduction in the late first half of the twentieth century, the use of ultrasonic appliances for various industrial applications has increased. Along with this growth in dissemination, the exposure of workers to airborne ultrasound also increased. In this paper we present the analysis of two data sets comprising 131 measurements at ultrasound associated workplaces in Germany. The data sets were individually acquired by the Institute for Occupational Safety and Health (IFA) and by the German Social Accident Insurance Institution for the energy, textile, electrical and media products sectors (BG ETEM). The data were analysed for abundance of certain machine categories and for transgression of threshold values according to German national guidelines. Machine categories were formed by combining machine type and working frequency. The results show that threshold transgressions occur at a considerable amount of workplaces at ultrasonic welding machines of certain frequencies. © 2018 The Author(s). Published by S. Hirzel Verlag · DOI: 10.3813/AAA.919212
EAA. This is an open access article under the terms of the Creative Commons Attribution (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).
S. Hirzel Verlag
10.3813/AAA.919212
ChristianUllisch-Nelken
AndreaWolff
HeikoKusserow
article
Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold - Evidence from fMRI.
PLOS ONE
2017
4
12
19
In the present study, the brain's response towards near- and supra-threshold infrasound (IS) stimulation (sound frequency < 20 Hz) was investigated under resting-state fMRI conditions. The study involved two consecutive sessions. In the first session, 14 healthy participants underwent a hearing threshold-as well as a categorical loudness scaling measurement in which the individual loudness perception for IS was assessed across different sound pressure levels (SPL). In the second session, these participants underwent three resting-state acquisitions, one without auditory stimulation (no-tone), one with a monaurally presented 12-Hz IS tone (near-threshold) and one with a similar tone above the individual hearing threshold corresponding to a 'medium loud' hearing sensation (supra-threshold). Data analysis mainly focused on local connectivity measures by means of regional homogeneity (ReHo), but also involved independent component analysis (ICA) to investigate inter-regional connectivity. ReHo analysis revealed significantly higher local connectivity in right superior temporal gyrus (STG) adjacent to primary auditory cortex, in anterior cingulate cortex (ACC) and, when allowing smaller cluster sizes, also in the right amygdala (rAmyg) during the near-threshold, compared to both the supra-threshold and the no-tone condition. Additional independent component analysis (ICA) revealed large-scale changes of functional connectivity, reflected in a stronger activation of the right amygdala (rAmyg) in the opposite contrast (no-tone > near-threshold) as well as the right superior frontal gyrus (rSFG) during the near-threshold condition. In summary, this study is the first to demonstrate that infrasound near the hearing threshold may induce changes of neural activity across several brain regions, some of which are known to be involved in auditory processing, while others are regarded as keyplayers in emotional and autonomic control. These findings thus allow us to speculate on how continuous exposure to (sub-)liminal IS could exert a pathogenic influence on the organism, yet further (especially longitudinal) studies are required in order to substantialize these findings.
https://www.ncbi.nlm.nih.gov/pubmed/28403175
MarkusWeichenberger
ChristianKoch
Jü.Gallinat
BerndIttermann
AlbrechtIhlenfeld
CGForlim
JohannesHensel
RobertKühler
MartinBauer
SimoneKühn
article
Hearing beyond the limit: Measurement, perception and impact of infrasound and ultrasonic noise
12 th ICBEN Congress on noise as a public health problem, 2017
2017
In our daily lives, many sources emit infrasound due to their functions or as a side effect. At
the other end of the hearing frequency range, airborne ultrasound is applied in many technical
and medical processes and has also increasingly moved into everyday life. There are numerous indicators that sound at these frequencies can be perceived and can influence human
beings. However, the precise mechanisms of this perception are unknown at present and this
lack of understanding is reflected by the unsatisfactory status of the existing regulations and
standards. In this paper, the current status of measurement capabilities, the knowledge about
perception mechanisms, and the assessment of infrasound and airborne ultrasound are
described. To contribute to the question of whether these sounds may be of any risk to the
hearing system, the results of several studies using audiological methods and neuroimaging
are presented. They were implemented within an EU-funded international project in order to
improve the objective understanding of the auditory perception of infrasound and airborne
ultrasound in humans.
http://www.icben.org/2017/ICBEN%202017%20Papers/Keynote02_Koch_4163.pdf
ChristianKoch
M.(ED.)Brink
article
Hearing threshold measurements of infrasound combined with audio frequency sound
12 th ICBEN Congress on noise as a public health problem, 2017
2017
Within the framework of the European project EMPIR 15HLT03 "Ears II" this study aims at a
better understanding of the human response to infrasound. The purpose of this study is to
examine which role the combination of infrasound (< 20 Hz) and sound in the audio frequency
range (between 20 Hz and 20 kHz) plays for the perception of infrasound. One hypothesis to
be validated is that the interaction between infrasound and audio-frequency sound may
explain the perceptibility of infrasound. Another aim is to investigate whether the presence of
infrasound influences the hearing threshold of audio frequency sound.
In order to test these hypotheses detection threshold measurements were performed
separately for infrasound and audio-frequency sound stimuli. Then thresholds were measured
for infrasound stimuli in the presence of audio-frequency sound and for audio-frequency
sound stimuli in the presence of infrasound.
The measurement setup consisted of an infrasound source and an audio-frequency sound
source, each coupled by a sound tube to the same eartip that was used for monaural
presentation of the acoustic stimuli.
http://www.icben.org/2017/ICBEN 2017 Papers/SubjectArea10_Burke_1002_3574.pdf
ElisaBurke
JohannesHensel
ThomasFedtke
M.(ED.)Brink
article
Comment on "Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air?"
Proc. R. Soc. A 473: 20160828.
2017
T. G.Leighton
article
Investigation of hearing perception at ultrasound frequencies by functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG)
PROCEEDINGS of the 22nd International Congress on Acoustics
2016
9
Airborne ultrasound is applied in many technical and medical processes and has increasingly moved into daily life. Because of a potential exposure of humans the question whether sound at these frequencies can be heard and whether these sounds can be of any risk for the hearing system or for wellbeing and health of an individual in general, is of great practical relevance. To study these issues audiological methods and neuroimaging were combined in order to obtain an objective rationale of the auditory perception of airborne ultrasound in humans. In a first step the monaural pure-tone hearing threshold for 26 young test subjects (19 – 33 years) in the frequency range from 14 to 24 kHz was determined. The hearing threshold values rose steeply with increasing frequency up to around 21 kHz followed by a range with smaller slope towards 24 kHz. In a next step neuroimaging techniques were applied to find brain activation following the stimulation by ultrasound between 20 and 24 kHz. Functional magnetic resonance imaging (fMRI) with sound pressure levels slightly above and below individual threshold was used in experiments with the same test persons as in the audiological measurements. Although test subjects reported audible sensation no brain activation could be identified in the above-threshold case except for the lowest test frequency at 14 kHz. Magnetoencephalography (MEG) was employed as an alternative method with the same test person group. Brain activation was measured, but again no auditory cortex activation was found above 14 kHz.
RobertKühler
MarkusWeichenberger
MartinBauer
SimoneKühn
TilmannSander-Thömmes
AlbrechtIhlenfeld
BerndIttermann
JohannesHensel
ChristianKoch
article
The calibration of a prototype occluded ear simulator designed for neonatal hearing assessment applications
The Journal of the Acoustical Society of America 140, 806
2016
An innovative family of ear simulators has been conceived for the calibration and traceability of audiometric equipment. Each device within the family has been designed for a particular key age group, covering neonates through to adults. The age-specific ear simulators are intended to improve the quality of hearing assessment measurements for all test subject age groups, and will be proposed as the next generation of standardised ear simulators for audiometric applications. The family of ear simulators shares a common design and modeling approach, and the first prototype devices for neonatal applications have been manufactured. The objectives of this study were to develop calibration methods, verify conformance to the design goals, demonstrate that the device is capable of being calibrated reliably, and show that its performance is ultimately suitable for international standardisation and eventual adoption into clinical practices. Four national measurement institutes took part in a round-robin calibration comparison and an analysis of the results showed that these objectives were achieved.
The Journal of the Acoustical Society of America 140, 806 (2016); https://doi.org/10.1121/1.4960517
RichardBarham
DominiqueRodrigues
SalvadorBarrera Figueroa
ErlingSandermann Olsen
EnverSadikoğlu
BakiKaraböce
article
Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air?
Proc. Roy. Soc. A
2016
472(2185)
10.1098/rspa.2015.0624
T. G.Leighton
article
Evaluation of cost-efficient auditory MEG stimulation
Advanced Mechatronics Solutions
2016
153-158
RobertKühler
JohannesHensel
T.Palko
TilmannSander-Thömmes
article
Design of a new ear simulator
Proceedings of Internoise 2015
2015
250 (4)
3031-3039
DominiqueRodrigues
ThomasLavergne
ErlingSandermann Olsen
RichardBarham
ThomasFedtke
J.-N.Durocher
article
MEG and fMRI localization of infrasonic and low-frequency sound
Proccedings of the ISMRM 2015 - International Society for Magnetic Resonance in Medicine
2015
MarkusWeichenberger
SimoneKühn
BerndIttermann
ChristianKoch
JohannesHensel
AlbrechtIhlenfeld
RobertKühler
MartinBauer
Rü.Brühl
TilmannSander-Thömmes
article
Measurement and assessment of airborne ultrasound noise
Proceedings of Congress on Sound and Vibration, ICSV 22
2015
ChristophKling
ChristianKoch
RobertKühler
article
Investigation of perception at infrasound frequencies by functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG)
Congress on Sound and Vibration, ICSV 22
2015
MartinBauer
TilmannSander-Thömmes
AlbrechtIhlenfeld
SimoneKühn
RobertKühler
ChristianKoch
article
Auditory cortex activation by infrasonic and low-frequency sound of equalised individual loudness
Euronoise 2015
2015
2577-2582
RobertKühler
JohannesHensel
ChristianKoch
MartinBauer
TilmannSander-Thömmes
article
Methodology of Designing an Occluded Ear Simulator
Acta Acustica united with Acustica
2015
101
1007-1015
1
DominiqueRodrigues
ThomasLavergne
E. S.Olsen
ThomasFedtke
RichardBarham
J.-N.Durocher
article
Magnetoencephalographic accuracy profiles for the detection of auditory pathway sources
Biomed. Technik
2015
60
135-145
MartinBauer
TilmannSander-Thömmes
article
Brief bursts of infrasound may improve cognitive function--An fMRI study
Hearing research
2015
328
87-93
MarkusWeichenberger
TilmannSander-Thömmes
ChristianKoch
Jü.Gallinat
BerndIttermann
AlbrechtIhlenfeld
Rü.Brühl
JohannesHensel
MartinBauer
RobertKühler
SimoneKühn
article
Infrasonic and low-frequency insert earphone hearing threshold
J Acoust Soc Am
2015
137(4)
1
RobertKühler
ThomasFedtke
JohannesHensel
article
Investigation of the m100 brain response to low frequency sound simulation
Biomagnetism Conference (Biomag)
2014
55
MartinBauer
RobertKühler
JohannesHensel
ChristophKling
ChristianKoch
TilmannSander-Thömmes
article
Magnetoencephalography of deep lying auditory sources using acoustical devices for infra- and ultrasound stimulation
Biomed Tech
2013
58
10.1515/bmt-2013-4135
MartinBauer
B.Piper
RobertKühler
RichardBarham
JohannesHensel
ChristophKling
ChristianKoch
TilmannSander-Thömmes
article
Extending the frequency range of free-field reciprocity calibration of measurement microphones to frequencies up to 150 kHz
Proceedings of Internoise 2013
2013
3898
SalvadorBarrera Figueroa
AntoniTorras Rosell
FinnJacobsen
article
Methodology of designing an ear simulator
Proceedings of Internoise 2013
2013
vol5
3876
DominiqueRodrigues
ThomasLavergne
ThomasFedtke
ErlingSandermann Olsen
RichardBarham
J.-N.Durocher
article
Universal ear simulator: Specifications and artificial ear canal design
Proceedings of Internoise 2013
2013
vol 5
3882
ThomasLavergne
DominiqueRodrigues
VeraNeimanns
ErlingSandermann Olsen
RichardBarham
article
New study on human perception on non-audible sound
Proceedings of the 20th International Congress on Sound and Vibration 2013 (ICSV20)
2013
3215-3220
RichardBarham
C.Baker
B.Piper
TilmannSander-Thömmes
article
A simple electrical lumped-element model simulates intra-cochlear sound pressures and cochlear impedance below 2 kHz
J Acoust Soc Am
2013
134(5)
3730-3738
1
TorstenMarquardt
JohannesHensel
article
What is ultrasound?
Progress in Biophysics and Molecular Biology
2007
93(1-3)
3-83
10.1016/j.pbiomolbio.2006.07.026
T. G.Leighton
article
Noise exposure at ultrasound-related industrial workplaces and public sites
The dataset contains single measurements at different public sites and workplaces in Europe. The data has been used or obtained in the context of the project 15HLT03 “EarsII” from the EMPIR-programme.
For each measurement metadata is available. This includes the measurement circumstances and involved machinery, a description of the measurement location and noise reduction measures, the microphone position during measurement, and the measurement procedure used to obtain the measurement data.
A detailed description of all the quantities contained in the dataset is documented in the accompanying pdf-file.
DOI:10.5281/zenodo.3163216
AndreaWolff
ChristianUllisch-Nelken
R.Schöneweiß
ChristophKling
HeikoKusserow
M.D.Fletcher
article
Free-field sensitivity of four electro-acoustic measuring chains at 0° incidence angle in the frequency range 0.25 kHz to 100 kHz
This dataset contains calibration data of the free-field sensitivity of four electro-acoustic measuring chains at 0° incidence angle in the frequency range 0.25 kHz to 100 kHz. Each of the four channels consisted of a ¼'' externally polarized free-field measurement microphone of the condenser type GRAS 40 BF, a ¼'' preamplifier GRAS 26AC, a power module GRAS 12AQ and an FFT analyzer Ono Sokki CF-9400. The calibration data was acquired in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB).
DOI: 10.5281/zenodo.3552412
R.Schöneweiß
ChristophKling
ChristianKoch