Development of a fast method for determining sensitivity to temporal fine structure.

Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge, UK.
International journal of audiology (Impact Factor: 1.43). 01/2009; 48(4):161-71. DOI: 10.1080/14992020802475235
Source: PubMed

ABSTRACT Recent evidence suggests that sensitivity to the temporal fine structure (TFS) of sounds is adversely affected by cochlear hearing loss. This may partly explain the difficulties experienced by people with cochlear hearing loss in understanding speech when background sounds, especially fluctuating backgrounds, are present. We describe a test for assessing sensitivity to TFS. The test can be run using any PC with a sound card. The test involves discrimination of a harmonic complex tone (H), with a fundamental frequency F0, from a tone in which all harmonics are shifted upwards by the same amount in Hertz, resulting in an inharmonic tone (I). The phases of the components are selected randomly for every stimulus. Both tones have an envelope repetition rate equal to F0, but the tones differ in their TFS. To prevent discrimination based on spectral cues, all tones are passed through a fixed bandpass filter, usually centred at 11F0. A background noise is used to mask combination tones. The results show that, for normal-hearing subjects, learning effects are small, and the effect of the level of testing is also small. The test provides a simple, quick, and robust way to measure sensitivity to TFS.

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Available from: Brian C J Moore, Jul 02, 2015
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    ABSTRACT: Objective: To extend the study of Hopkins and Moore (2011) by examining the effect of age in the medium age range on sensitivity to temporal fi ne structure (TFS), which is assumed to be represented in the patterns of phase locking in the auditory nerve. Design: Monaural TFS sensitivity was assessed using the TFS1 test (Moore & Sek, 2009) at centre frequencies of 850 and 2000 Hz, and binaural TFS sensitivity was assessed using the TFS-LF test (Hopkins & Moore, 2010a) at centre frequencies of 500 and 850 Hz, using a sensation level of 30 dB. Study sample: Thirty-fi ve newly recruited normal-hearing subjects (thresholds better than 20 dB HL from 250 to 6000 Hz) were tested. Their ages ranged from 22 to 61 years. Results: There was a signifi cant correlation between age and TFS sensitivity at all frequencies for both TFS tests. For the single centre frequency (850 Hz) that was used for both tests, scores for the two tests were modestly but signifi cantly correlated. Conclusions: Sensitivity to TFS decreases with increasing age. The monaural and binaural TFS tests appear to reflect at least somewhat distinct auditory processes.
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