Implementation of two tests for measuring sensitivity to temporal fine structure

Objective: To implement two methods for measuring sensitivity to temporal fine structure (TFS) for use in assessing effects of hearing loss and age that may not be apparent from the audiogram. Design: The TFS1 test was described by Moore and Sek (2009). The task is to discriminate a harmonic complex tone from a tone in which all frequency components are shifted upwards by the same amount in Hz. The TFSLF test was described by Hopkins and Moore (2010a). The task is to detect changes in lateral position of a binaurally presented tone based on interaural phase difference (IPD). Both tests have been implemented in software that can be run on a PC with a good-quality sound card. The software includes a routine for measuring the absolute threshold at the test frequency. Results: For each test, an experimental run at a single frequency takes about three minutes. Practice tasks (frequency discrimination of pure tones for TFS1 and discrimination of changes in lateral position based on interaural level difference for TFSLF) are also implemented that are similar to the main task, but easier. Conclusions: The software implementation allows sensitivity to TFS to be measured quickly without a requirement for specialized equipment.