Leighton, T. G. (2016). Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air? Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 472(2185).
Added by: Mark Grimshaw-Aagaard 07/11/2023, 11:31
"recent data suggest 1 in 20 people aged 40–49 years have hearing thresholds that are at least 20 dB more sensitive at 20 kHz than that of the average 30–39 year old. Moreover, 5% of the 5–19 year age group is reported to have a 20 kHz threshold that is 60 dB more sensitive than the median for the 30–39 year age group"
"For over 40 years, there have been reports of hearing threshold shift . . . and a range of subjective effects (nausea, dizziness, migraine, fatigue, tinnitus and ‘pressure in the ears’ . . .) from ultrasound in air to which workers have been routinely exposed (plus other symptoms that have not occurred in more than one study . . .). The degree of response, from significant to none, varied between workers. The evidence base has not studied sufficient numbers of subjects, and has not been sufficiently sensitive to the presence of sensitive individuals, or sensitive subgroups, within the population, to support the guidelines required today. Studies focused on occupational exposure to ultrasound, which tends also to occur alongside high levels of audible sound, and the effect of this audio frequency noise on the observed effects must be isolated because there is increasing public exposure to ultrasound without such audible cues. Measurement methods and audiological procedures in the past have tended to follow extrapolations of methods used in the audio frequency range which, alongside the calibrations and allowed tolerances of the equipment used, must be critically examined . . . . It is therefore no simple matter to measure the very high frequency/ultrasonic (VHF/US) fields to which people are exposed, either in situ or during audiological testing, and relate those to the levels quoted in past studies. Consequently, the evidence to date has been wholly inadequate to inform the development of guidelines for the increasing exposure of the public to ultrasound in air, and is suspect for occupational exposure."
Leighton, T. G. (2017). Comment on ‘Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air?’. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 473(2199), 20160828.
Added by: Mark Grimshaw-Aagaard Last edited by: Mark Grimshaw-Aagaard 07/11/2023, 11:33
