The Spectral Extent of Phasic Suppression of Loudness and Distortion-Product Otoacoustic Emissions by Infrasound and Low-Frequency Tones

Marcelo Larrea,Juan Vizuete,Alain de Cheveigné,Torsten Marquardt,Carlos Jurado,Man Yui Pat Chow,Ka Man Lydia Leung

doi:10.1007/s10162-021-00830-2

Abstract

We investigated the effect of a biasing tone close to 5, 15, or 30 Hz on the response to higher-frequency probe tones, behaviorally, and by measuring distortion-product otoacoustic emissions (DPOAEs). The amplitude of the biasing tone was adjusted for criterion suppression of cubic DPOAE elicited by probe tones presented between 0.7 and 8 kHz, or criterion loudness suppression of a train of tone-pip probes in the range 0.125–8 kHz. For DPOAEs, the biasing-tone level for criterion suppression increased with probe-tone frequency by 8–9 dB/octave, consistent with an apex-to-base gradient of biasing-tone-induced basilar membrane displacement, as we verified by computational simulation. In contrast, the biasing-tone level for criterion loudness suppression increased with probe frequency by only 1–3 dB/octave, reminiscent of previously published data on low-side suppression of auditory nerve responses to characteristic frequency tones. These slopes were independent of biasing-tone frequency, but the biasing-tone sensation level required for criterion suppression was ~ 10 dB lower for the two infrasound biasing tones than for the 30-Hz biasing tone. On average, biasing-tone sensation levels as low as 5 dB were sufficient to modulate the perception of higher frequency sounds. Our results are relevant for recent debates on perceptual effects of environmental noise with very low-frequency content and might offer insight into the mechanism underlying low-side suppression.

Highlights

It has long been known that low-frequency tones can mask high-frequency probe tones across a large spectral distance (Wegel and Lane 1924)
As the 5-Hz biasing tones (BTs) required generally higher sound pressure levels that almost always reached the safety limit for f2 > 1 kHz, very few distortion-product otoacoustic emissions (DPOAEs) suppression data could be obtained with this BT
Our initial assumption was that the two methods probed the same phenomenon, a shift of the operating point of the mechano-electrical transducer of the outer hair cells (OHCs) in response to the BT, and that combining them would allow us extend the probe frequency range of our measurements

Summary

Introduction

It has long been known that low-frequency tones can mask high-frequency probe tones across a large spectral distance (Wegel and Lane 1924). The effect is not unexpected, supposing non-linear interaction between probe and suppressor, given that the travelling wave evoked by the suppressor traverses basal high-frequency regions characteristic of the probe on the BM. The travelling wave amplitude increases as it approaches the suppressor’s characteristic place, which explains why the suppressive effect increases with spectral proximity between probe stimulus. We attempted to quantify the slope of the suppressor excitation pattern for the human ear

Methods

Results

Conclusion