Nonlinear explanation for bone-conducted ultrasonic hearing

Fujimoto, Kiyoshi; Nakagawa, Seiji; Tonoike, Mitsuo

doi:10.1016/j.heares.2005.02.004

Cited by 33 publications

(25 citation statements)

References 13 publications

(27 reference statements)

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“…There is a wealth of material on mechanisms for acuity [176][177][178][179][180][181][182] although a great deal is based on bone conduction rather than the airborne pathway. The issue to be addressed in §4b is whether there is a mechanism for adverse effects without hearing acuity.…”

Section: (5) Mosquitomentioning

confidence: 99%

Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air?

Leighton¹

2016

Proc. R. Soc. A.

125

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New measurements indicate that the public are being exposed, without their knowledge, to airborne ultrasound. Existing guidelines are insufficient for such exposures; the vast majority refers to occupational exposure only (where workers are aware of the exposure, can be monitored and can wear protection). Existing guidelines are based on an insufficient evidence base, most of which was collected over 40 years ago by researchers who themselves considered it insufficient to finalize guidelines, but which produced preliminary guidelines. This warning of inadequacy was lost as nations and organizations issued ‘new’ guidelines based on these early guidelines, and through such repetition generated a false impression of consensus. The evidence base is so slim that few reports have progressed far along the sequence from anecdote to case study, to formal scientific controlled trials and epidemiological studies. Early studies reported hearing threshold shifts, nausea, headache, fatigue, migraine and tinnitus, but there is insufficient research on human subjects, and insufficient measurement of fields, to assess what health risk current occupational and public exposures might produce. Furthermore, the assumptions underpinning audiology and physical measurements at high frequencies must be questioned: simple extrapolation of approaches used at lower frequencies does not address current unknowns. Recommendations are provided.

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Section: (5) Mosquitomentioning

confidence: 99%

Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air?

Leighton¹

2016

Proc. R. Soc. A.

125

View full text Add to dashboard Cite

show abstract

“…In contrast, if the pitch under AM DSB-SC condition was twice as high as that under AM DSB-TC condition, the distortion products generated from the two ultrasonic side bands might be important in the pitch perception of modulated BCU. Fujimoto et al (2005) found that ultrasonic AM DSB-TC signals produced pitch perception corresponding to that from air-conducted pure tones, while ultrasonic AM DSB-SC signals produced pitch perception as if from tones with double frequencies. They concluded that a nonlinear process contributed to the perception of modulated BCU.…”

Section: Introductionmentioning

confidence: 92%

“…Because a modulated signal contains multiple frequency components, a nonlinear process may readily produce distortion products. Fujimoto et al (2005) measured difference limens for frequency (DLFs) of BCU modulated by air-conducted pure tones under two conditions: using amplitude modulation based on a double side band transmitted carrier (AM DSB-TC), and a suppressed carrier (AM DSB-SC). When BCU carrier is modulated by an ACAS signal, the stimulus includes the side bands whose frequency is equal to the carrier frequency plus or minus the signal frequency.…”

Section: Introductionmentioning

confidence: 99%

Peripheral perception mechanism of ultrasonic hearing

et al. 2011

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“…Fujimoto, Nakagawa and Tonoike [19] and Lenhardt [20] showed that bone-conducted ultrasounds masked (increased the detection threshold) signals of 10-14 kHz and even up to 19 kHz transmitted through the air pathway [14]. Ultrasounds of 12-16 kHz masking bone-conduction caused an increase in the hearing threshold by 15-22 dB.…”

Section: Effects Of Ultrasonic Noise On Hearingmentioning

confidence: 99%

“…Most countries assess ultrasonic noise by measuring equivalent sound pressure level in one-third-octave bands referred to 8-h noise exposure at workstations [2]. France determines admissible values of ultrasonic noise and recommends limiting noise exposure in the high audible frequency range (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and the low-frequency ultrasonic range (20-50 kHz). In Poland, ultrasonic noise is assumed, for practical reasons, as noise whose spectrum includes high audible and low ultrasonic frequencies (i.e., 10-40 kHz) [3].…”

Section: Introductionmentioning

confidence: 99%