A discrimination task can isolate temporal fine structure sensitivity from excitation-pattern cues.

Evidence

Monaural TFS processing has also been assessed using the TFS1 test (Hopkins and Moore 2007 ; Moore and Sek 2009 ). This requires discrimination of a harmonic complex tone (H) from an inharmonic tone (I), created by shifting all components in the H tone up by a fixed amount in hertz, ∆f. The value of ∆f is adaptively varied to determine the threshold. Both tones are passed through a fixed bandpass filter centred on the higher (unresolved) components, and a background noise is used to mask combination tones and components falling on the skirts of the filter. Evidence suggesting that performance on this test reflects sensitivity to TFS rather than the use of excitation-pattern cues is: (1) Performance on the TFS test does not worsen with increasing level, except when the level is very high (Moore and Sek 2009 , 2011 ; Marmel et al. 2015 ); (2) Randomizing the level of the individual components would be expected to impair the ability to use excitation-pattern cues, but this has very little effect on performance of the TFS1 test (Jackson and Moore 2014 ); (3) Differences in excitation level between the H and I tones at the threshold value of ∆f, estimated using the H and I tones as forward maskers, are too small to be usable (Marmel et al. 2015 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 797

Categorization

• DEFINE: Defines the TFS1 test and the three control experiments that establish it isolates TFS processing from place/excitation cues.