Responses of cochlear nucleus neurons to harmonic and mistuned complex tones

Sinex, Donal G.

doi:10.1016/j.heares.2007.11.001

Cited by 21 publications

(23 citation statements)

References 39 publications

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“…In the current study, it is likely that the effects of age on the cochlea were similar in older musicians and nonmusicians, as there were no differences in their pure-tone thresholds. Although we did not investigate subcortical responses, it is likely that the ORN is related to processing of the mistuned harmonic in subcortical structures (Sinex, 2008;Sinex, Guzik, Li, & Sabes, 2003;Sinex, Sabes, & Li, 2002). Thus, although the ORN is generated along the superior temporal plane, ORN generation likely depends on earlier processing of the mistuned harmonic in subcortical structures.…”

Section: Discussionmentioning

confidence: 95%

The Influence of Lifelong Musicianship on Neurophysiological Measures of Concurrent Sound Segregation

Zendel

Alain

2013

Journal of Cognitive Neuroscience

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The ability to separate concurrent sounds based on periodicity cues is critical for parsing complex auditory scenes. This ability is enhanced in young adult musicians and reduced in older adults. Here, we investigated the impact of lifelong musicianship on concurrent sound segregation and perception using scalp-recorded ERPs. Older and younger musicians and nonmusicians were presented with periodic harmonic complexes where the second harmonic could be tuned or mistuned by 1-16% of its original value. The likelihood of perceiving two simultaneous sounds increased with mistuning, and musicians, both older and younger, were more likely to detect and report hearing two sounds when the second harmonic was mistuned at or above 2%. The perception of a mistuned harmonic as a separate sound was paralleled by an object-related negativity that was larger and earlier in younger musicians compared with the other three groups. When listeners made a judgment about the harmonic stimuli, the perception of the mistuned harmonic as a separate sound was paralleled by a positive wave at about 400 msec poststimulus (P400), which was enhanced in both older and younger musicians. These findings suggest attention-dependent processing of a mistuned harmonic is enhanced in older musicians and provides further evidence that age-related decline in hearing abilities are mitigated by musical training.

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Section: Discussionmentioning

confidence: 95%

The Influence of Lifelong Musicianship on Neurophysiological Measures of Concurrent Sound Segregation

Zendel

Alain

2013

Journal of Cognitive Neuroscience

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“…Sinex and coworkers (Sinex, 2008; Sinex and Li, 2007) measured responses to concurrent harmonic complexes in the IC and cochlear nucleus (CN) of anesthetized chinchillas. In the IC, the responses to double harmonic complexes showed little or no synchrony to individual harmonics, and usually followed envelope fluctuations resulting from beats between adjacent components (Sinex and Li, 2007).…”

Section: Neural Basis Of the Perception Of Concurrent Harmonic Soundsmentioning

confidence: 99%

“…In contrast, Chopper neurons exhibited little synchrony to individual components, and tended to follow envelope fluctuations resulting from interactions between adjacent components (Sinex, 2008). Based on these results and earlier ones, which showed that ANFs typically synchronized to individual components in harmonic complex tones or complex tones containing a mistuned component (Sinex et al, 2003), Sinex (2005, 2008) suggested that neural responses to complex tones undergo a major transformation at the level of the lower brainstem, which results in qualitatively different responses to harmonic and inharmonic stimuli below and above the CN. Below the CN, neurons usually synchronize to individual components in a complex tone, regardless of whether these components are harmonically related or not.…”

Section: Neural Basis Of the Perception Of Concurrent Harmonic Soundsmentioning

confidence: 99%

Pitch, harmonicity and concurrent sound segregation: Psychoacoustical and neurophysiological findings

Micheyl¹,

Oxenham²

2010

Hearing Research

114

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Harmonic complex tones are a particularly important class of sounds found in both speech and music. Although these sounds contain multiple frequency components, they are usually perceived as a coherent whole, with a pitch corresponding to the fundamental frequency (F0). However, when two or more harmonic sounds occur concurrently, e.g., at a cocktail party or in a symphony, the auditory system must separate harmonics and assign them to their respective F0s so that a coherent and veridical representation of the different sounds sources is formed. Here we review both psychophysical and neurophysiological (single-unit and evoked-potential) findings, which provide some insight into how, and how well, the auditory system accomplishes this task. A survey of computational models designed to estimate multiple F0s and segregate concurrent sources is followed by a review of the empirical literature on the perception and neural coding of concurrent harmonic sounds, including vowels, as well as findings obtained using single complex tones with “mistuned” harmonics.

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“…Only a few studies have directly examined the representation of the F0s of concurrent complex tones in the AN and CN (Palmer 1990, 1992; Tramo et al 2000; Keilson et al 1997; Sinex 2008). Using two concurrent vowels with F0s of 100 and 125 Hz, Palmer found that the temporal discharge patterns of AN fibers contained sufficient information to identify both F0s.…”

Section: Introductionmentioning

confidence: 99%

Pitch Representations in the Auditory Nerve: Two Concurrent Complex Tones

Larsen

Cedolin²,

Delgutte³

2008

Journal of Neurophysiology

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Pitch differences between concurrent sounds are important cues used in auditory scene analysis and also play a major role in music perception. To investigate the neural codes underlying these perceptual abilities, we recorded from single fibers in the cat auditory nerve in response to two concurrent harmonic complex tones with missing fundamentals and equal-amplitude harmonics. We investigated the efficacy of rate-place and interspike-interval codes to represent both pitches of the two tones, which had fundamental frequency (F0) ratios of 15/14 or 11/9. We relied on the principle of scaling invariance in cochlear mechanics to infer the spatiotemporal response patterns to a given stimulus from a series of measurements made in a single fiber as a function of F0. Templates created by a peripheral auditory model were used to estimate the F0s of double complex tones from the inferred distribution of firing rate along the tonotopic axis. This rate-place representation was accurate for F0s above about 900 Hz. Surprisingly, rate-based F0 estimates were accurate even when the two-tone mixture contained no resolved harmonics, so long as some harmonics were resolved prior to mixing. We also extended methods used previously for single complex tones to estimate the F0s of concurrent complex tones from interspike-interval distributions pooled over the tonotopic axis. The interval-based representation was accurate for F0s below about 900 Hz, where the two-tone mixture contained no resolved harmonics. Together, the rate-place and interval-based representations allow accurate pitch perception for concurrent sounds over the entire range of human voice and cat vocalizations.

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Responses of cochlear nucleus neurons to harmonic and mistuned complex tones

Cited by 21 publications

References 39 publications

The Influence of Lifelong Musicianship on Neurophysiological Measures of Concurrent Sound Segregation

The Influence of Lifelong Musicianship on Neurophysiological Measures of Concurrent Sound Segregation

Pitch, harmonicity and concurrent sound segregation: Psychoacoustical and neurophysiological findings

Pitch Representations in the Auditory Nerve: Two Concurrent Complex Tones

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