Auditory model responses to harmonic and inharmonic complex tones: Effects of the cochlear amplifier

Authors

  • Václav Vencovský Musical Acoustics Research Center, Academy of Performing Arts in Prague, Prague, Czech Republic

Abstract

Hopkins and Moore [J. Acoust. Soc. Am. 122, 1055-1068 (2007)] measured the ability of hearing-impaired (HI) listeners to discriminate harmonic (H) from inharmonic (I) – all harmonics shifted upwards by the same amount in Hz – complexes. The complexes were composed of many bandpass-filtered harmonics (shaped stimuli) or five equal-amplitude harmonics (non-shaped stimuli). HI listeners performed worse with the shaped stimuli than with the non-shaped stimuli. Since shaping of the complexes should minimize envelope and spectral cues, listeners should discriminate H from I stimuli mainly using temporal fine structure (TFS) cues even when the harmonics are not resolved. This ability seems to be worsened in HI listeners. This study employed an auditory model with a physical cochlear model to show how the cochlear amplifier affects responses to H and I stimuli. For the shaped stimuli, the TFS of the simulated neural signals for H and I stimuli differed, represented by low cross-correlation coefficients computed from the shuffled cross-polarity correlograms. However, for the passive auditory model (simulating HI), the inter-spike intervals smaller than half of the stimulus period were similar. This could explain the poor performance for HI listeners. For the non-shaped stimuli, differences in the inter-spike intervals were observed even for the passive model, which could contribute to the improved performance.

References

Glasberg, B.R. and Moore, B.C.J. (1990). “Derivation of auditory filter shapes from notched-noise data,” Hear. Res., 47, 103-138.

Hopkins, K. and Moore, B.C.J. (2007). “Moderate cochlear hearing loss leads to a reduced ability to use temporal fine structure information,” J. Acoust. Soc. Am., 122, 1055-1068.

Joris, P.X. (2003). “Interaural time sensitivity dominated by cochlea-induced envelope patterns,” J. Neurosci., 23, 6345-6350.

Kale, S., Micheyl, C., and Heinz, M.G. (2014). “Implications of Within-Fiber Temporal Coding for Perceptual Studies of F0 Discrimination and Discrimination of Harmonic and Inharmonic Tone Complexes,” J. Assoc. Res. Otolaryngol., 15, 465-482.

Matlab Auditory Periphery (MAP). University of Essex, Hearing Research Laboratory: http://www.essex.ac.uk/psychology/department/hearinglab/modelling.html.

Meddis, R. (2006). “Auditory-nerve first-spike latency and auditory absolute threshold: A computer model,” J. Acoust. Soc. Am., 119, 406-417.

Nobili, R., Vetesnik, A., Turicchia, L., and Mammano, F. (2003). “Otoacoustic emissions from residual oscillations of the cochlear basilar membrane in a human ear model,” J. Assoc. Res. Otolaryngol., 4, 478-494.

Oxenham, A., Micheyl, C., and Keebler, M.V. (2009). “Can temporal fine structure represent the fundamental frequency of unresolved harmonics,” J. Acoust. Soc. Am., 125, 2189-2199.

Santurette, S., Dau, T., and Oxenham, A.J. (2012). “On the possibility of a place code for the low pitch of high-frequency complex tones,” J. Acoust. Soc. Am., 132, 3883-3895.

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Published

2015-12-15

How to Cite

Vencovský, V. (2015). Auditory model responses to harmonic and inharmonic complex tones: Effects of the cochlear amplifier. Proceedings of the International Symposium on Auditory and Audiological Research, 5, 197–204. Retrieved from https://proceedings.isaar.eu/index.php/isaarproc/article/view/2015-23