Comparison of cochlear delay estimates using otoacoustic emissions and auditory brainstem responses

Proc. Natl. Acad. Sci. U.S.A.

Mehta

Oxenham

2017

In modern Western music, melody is commonly conveyed by pitch changes in the highest-register voice, whereas meter or rhythm is often carried by instruments with lower pitches. An intriguing and recently suggested possibility is that the custom of assigning rhythmic functions to lower-pitch instruments may have emerged because of fundamental properties of the auditory system that result in superior time encoding for low pitches. Here we compare rhythm and synchrony perception between low-and high-frequency tones, using both behavioral and EEG techniques. Both methods were consistent in showing no superiority in time encoding for low over high frequencies. However, listeners were consistently more sensitive to timing differences between two nearly synchronous tones when the high-frequency tone followed the low-frequency tone than vice versa. The results demonstrate no superiority of low frequencies in timing judgments but reveal a robust asymmetry in the perception and neural coding of synchrony that reflects greater tolerance for delays of low-relative to high-frequency sounds than vice versa. We propose that this asymmetry exists to compensate for inherent and variable time delays in cochlear processing, as well as the acoustical properties of sound sources in the natural environment, thereby providing veridical perceptual experiences of simultaneity.rhythm perception | time encoding | sound asynchrony perception | auditory perception | mismatch negativity T he perception of music involves the processing of multiple simultaneous sounds, including the perceptual organization of components originating from one instrument into a single "auditory object" (1) and their segregation from components that originate from other instruments. The first stage of this process occurs in the inner ear and involves the decomposition of incoming sound by frequency, resulting in frequency-to-place mapping (tonotopy) along the length of the cochlear partition (2).A series of recent studies has suggested that these and other basic properties of the auditory system, which are shared by a wide variety of species, may help account for some fundamental aspects of Western music, including the dominance of high-register instruments (i.e., instruments with high fundamental frequencies) in carrying the melody (3-7), as well as the dominance of low-register instruments (such as bass or bass drum) in defining the meter or rhythm (8). In the latter case, a study by Hove et al. (8) involving both behavioral and EEG experiments reported that time encoding was superior for low-vs. high-pitched sounds and suggested that this superior time encoding could explain why low instruments generally lay the rhythm in music.The suggestion that superior time encoding of low pitches can explain aspects of Western music is intriguing. However, it runs contrary to the results from studies of many other types of auditory temporal processing, including gap detection (9), amplitude-modulation detection (10) and discrimination (11), and duration discrimination (12)...

Section: Discussionmentioning

confidence: 99%

Rhythm judgments reveal a frequency asymmetry in the perception and neural coding of sound synchrony

Proc. Natl. Acad. Sci. U.S.A.

Mehta

Oxenham

2017

“…Evidence from animal physiology Siegel et al, 2005;Temchin et al, 2005;Palmer and Shackleton, 2009;Temchin et al, 2011) and from measurements performed using non-invasive physiological techniques in humans (e.g., Elberling, 1974;Eggermont, 1979;Neely et al, 1988;Schoonhoven et al, 2001;Shera et al, 2002;Sisto and Moleti, 2007;Harte et al, 2009) shows that latencies of cochlear and auditory-nerve responses to low frequencies are longer than those for high-frequencies. Analysis of the relative across-frequency response timing at higher processing stages is complicated by non-homogeneity of the neural structures and responses in higher-level nuclei.…”

Section: B Cochlear Delays and Neural Synchrony Throughout The Auditmentioning

confidence: 99%

“…Noninvasive physiological measures of peripheral auditory responses in humans have shown that frequencydependent basilar-membrane (BM) traveling-wave delays result in a progressive delay of low frequencies relative to higher frequencies in the representation of a stimulus transmitted to the auditory nerve (AN) and subsequent processing stages (e.g., Elberling, 1974;Eggermont, 1979;Neely et al, 1988;Schoonhoven et al, 2001;Shera et al, 2002;Sisto and Moleti, 2007;Harte et al, 2009). Auditory brainstem responses (ABRs) to a chirp designed to counteract the frequency-dependent delays and to synchronize the BM responses across locations with different characteristic frequencies (CFs) exhibit a greater amplitude of wave V (Dau et al, 2000;Fobel and Dau, 2004), greater amplitudes of high-frequency (HF) components of the ABR spectrum, and a smaller phase variance of the main ABR components (Petoe et al, 2010b) than the ABRs to a click with the same overall energy.…”

Section: Introductionmentioning

confidence: 99%

Effects of temporal stimulus properties on the perception of across-frequency asynchrony

The Journal of the Acoustical Society of America

Beim

Micheyl

et al. 2013

The role of temporal stimulus parameters in the perception of across-frequency synchrony and asynchrony was investigated using pairs of 500-ms tones consisting of a 250-Hz tone and a tone with a higher frequency of 1, 2, 4, or 6 kHz. Subjective judgments suggested veridical perception of across-frequency synchrony but with greater sensitivity to changes in asynchrony for pairs in which the lower-frequency tone was leading than for pairs in which it was lagging. Consistent with the subjective judgments, thresholds for the detection of asynchrony measured in a threealternative forced-choice task were lower when the signal interval contained a pair with the lowfrequency tone leading than a pair with a high-frequency tone leading. A similar asymmetry was observed for asynchrony discrimination when the standard asynchrony was relatively small ( 20 ms) but not for larger standard asynchronies. Independent manipulation of onset and offset ramp durations indicated a dominant role of onsets in the perception of across-frequency asynchrony. A physiologically inspired model, involving broadly tuned monaural coincidence detectors that receive inputs from frequency-selective onset detectors, was able to accurately reproduce the asymmetric distributions of synchrony judgments. The model provides testable predictions for future physiological investigations of responses to broadband stimuli with across-frequency delays.

“…The BM delays have been estimated from measurements of the compound action potential (CAP) (Elberling, 1974;Eggermont, 1979;Schoonhoven et al, 2001), derived-bands and tone-burst auditory brainstem responses (Eggermont and Don, 1980;Neely et al, 1988;Don et al, 1993;Donaldson and Ruth, 1993;Don et al, 1998;Harte et al, 2009), distortion-product, transient-evoked, and stimulus-frequency otoacoustic emissions (Neely et al, 1988;Bowman et al, 1997;Ramotowski and Kimberley, 1998;Schoonhoven et al, 2001;Shera et al, 2002;Sisto and Moleti, 2007;Harte et al, 2009), and by using latency-frequency responses obtained postmortem (Von Békésy, 1949) and then assuming a compensation term for the effects of death on the cochlear function (Ruggero and Temchin, 2007). The latency (s) of peak BM responses has often been described by a power law, s ¼ af -b , where f is the tone frequency a and b are constants whose values differ across studies.…”

Section: Introductionmentioning

confidence: 99%

Perception of across-frequency asynchrony and the role of cochlear delays

The Journal of the Acoustical Society of America

Beim

Micheyl

et al. 2012

Cochlear filtering results in earlier responses to high than to low frequencies. This study examined potential perceptual correlates of cochlear delays by measuring the perception of relative timing between tones of different frequencies. A brief 250-Hz tone was combined with a brief 1-, 2-, 4-, or 6-kHz tone. Two experiments were performed, one involving subjective judgments of perceived synchrony, the other involving asynchrony detection and discrimination. The functions relating the proportion of "synchronous" responses to the delay between the tones were similar for all tone pairs. Perceived synchrony was maximal when the tones in a pair were gated synchronously. The perceived-synchrony function slopes were asymmetric, being steeper on the low-frequency-leading side. In the second experiment, asynchrony-detection thresholds were lower for low-frequency rather than for high-frequency leading pairs. In contrast with previous studies, but consistent with the first experiment, thresholds did not depend on frequency separation between the tones, perhaps because of the elimination of within-channel cues. The results of the two experiments were related quantitatively using a decision-theoretic model, and were found to be highly correlated. Overall the results suggest that frequency-dependent cochlear group delays are compensated for at higher processing stages, resulting in veridical perception of timing relationships across frequency.