Volume 32 #2

Contents

1. Tinnitus – contemporary knowledge about its origin, electrophysiological correlates and treatment
2. Eye optics and retinal topography in the nutria (Myocastor coypus)
3. Quantitative study of Poggendorff illusion in school children with normal binocular vision and with strabismus
4. The method of canine odor visualization
5. Precopulatory mechanisms of reproductive isolation between two chromosomal forms of striped hamsters Cricetulus barabensis sensu lato (Rodentia, Cricetinae)
6. Discrimination of sound signals with rippled spectra in on- and low-frequency noise: contribution of compressive nonlinearity and confounding issues
7. The equivalent frequency-tuned filter form for discrimination of spectral pattern of sound signals: Contribution of the lateral suppression and harmonics

Thresholds for spectral contrast of rippled (comb-filtered) spectrum sound signals were measured as a function of ripple density. The lowest thresholds (lower than 01.) were found at ripple densities of 3 to 4 oct–1. At lower densities (down to 1 oct–1) and higher densities (up to 6 oct–1) threshold increased. Additionally, the threshold dependence on ripple density featured fluctuations of periodicity of 1 oct–1. Threshold decrease at ripple densities around 4 oct–1 may be explained by spectral contrast sharpening due to lateral suppression. Threshold fluctuations of periodicity of 1 oct–1 may be explained by involvement of harmonics.

Key words: hearing, comb-filtered spectra, lateral suppression, contrast sharpening, harmonics

DOI: 10.7868/S0235009218020075

References:

• Bacon S.P., Boden L.N., Lee J., Repovsch J.L. Growth of simultaneous masking for fm < fc: effects of overall frequency and level. J. Fcoust. Soc. Am. 1999. V. 106. P. 341–350.
• Carterette F.C., Friedman M.P., Lovell J.D. Mach Bands in Hearing. J. Acoust. Soc. Am. 1969. V. 45. P. 986–998.
• Glasberg B.R., Moore B.C.J. Derivation of auditory filter shapes from notched-noise data Hearing Res. 1990. V. 47. P. 103–138.
• Houtgast T. Psychophysical evidence for lateral inhibition in hearing. J. Acoust. Soc. Am. 1972. V. 51. P. 1885–1894.
• Lopez-Poveda E.A., Plack C.J., Meddis R. Cochlear nonlinearity between 500 and 8,000 Hz in listeners with normal hearing. J. Acoust. Soc. Am. 2003. V. 113. P. 951–960.
• Nelson D.A., Schroder A.C., Wojtczak M. A new procedure for measuring peripheral compression in normal-hearing and hearing-impaired listeners. J. Acoust. Soc. Am. 2001. V. 110. P. 2045–2064.
• Oxenham A.J., Plack C.J. A behavioral measure of basilarmembrane nonlinearity in listeners with normal and impaired hearing. J. Acoust. Soc. Am. 1997. V. 101. P. 3666–3675.
• Patterson R. D., Nimmo-Smith I., Weber D. L., Milory R. The deterioration of hearing with age: Frequency selectivity, the critical ratio, the audiogram, and speech threshold. J. Acoust. Soc. Am. 1982. V. 72. P. 1788–1803.
• Rainbolt H., Small A.M. Mach bands in auditory masking: An attempted replication. J. Acoust. Soc. Am. 1972. V. 51. P. 567–574.
• Ruggero M.A., Robles L., Rich N.C. Two-tone suppression in the basilar membrane of the cochlea: Mechanical basis of auditory-nerve rate suppression. J. Neurophysiol. 1992. V. 68. P. 1087–1099.
• Sachs M.B., Kiang, N.Y. S. Two-Tone inhibition in auditorynerve fibers. J. Acoust. Soc. Am. 1968. V. 43. P. 1120–1128.
• Shannon R.V. Two-tone unmasking and suppression in a forward-masking situation. J. Acoust. Soc. Am. 1976. V. 59. P. 1460–1470.
• Small A.M. Mach bands in auditory masking revisited. J. Acoust. Soc. Am. 1975. V. 57. P. 251–252.
• Supin A. Ya., Popov V.V., Milekhina O.N., Tarakanov M.B. Ripple density resolution for various rippled-noise patterns. J. Acoust. Soc. Am. 1998. V. 103. P. 2042–2050.
• Zwicker E. Masking and psychophysical excitation as consequences of the ear’s frequency analysis. Frequency Analysis and Periodicity Detection in Hearing. Ed.R. Plomp, G.F. Smoorenburg. 1970. P. 376–394.