Clinical feasibility of fast psychophysical tuning curves evaluated using normally hearing adults: Success rate, range of tip shift, repeatability, and comparison of methods used for estimation of frequency at the tip
OBJECTIVE: Psychophysical tuning curves (PTCs) have been used predominantly in laboratory settings to assess frequency selectivity in the auditory system. Recently, a fast-PTC procedure has been developed for diagnosis of cochlear dead regions. In this study the clinical feasibility of using fast PTCs in adults was investigated. Success rate (the number of successes per number of attempts) and repeatability were assessed. The range of the tip frequency (ftip) shift was established and different methods of ftip estimation compared. DESIGN: Fast PTCs were measured for signal frequencies (fs) of 500, 1000, 2000, 3000, and 4000 Hz on two occasions using an upward-sweeping masker. Five methods were used to estimate ftip for each PTC. STUDY SAMPLE: Thirty-two adults with normal hearing were tested. RESULTS: All participants were able to successfully complete the task, the majority of them with minimal training. The moving average, quadratic function, and double lowpass filtering methods had the highest success rate in ftip estimation. The quadratic function method had the smallest 95% range of - 3.4% fs to 10.2% fs and the best test-retest reliability of 5.1% fs. CONCLUSIONS: Fast PTCs show potential for clinical use due to a high success rate with minimal training required. We suggest the quadratic function method for routine clinical use as it had the smallest 95% range, a high success rate in ftip estimation and the best test-retest reliability. For fast PTCs measured for signal frequencies from 500 to 4000 Hz using an upward-sweeping masker, we suggest the normative range of ftip to be - 3% fs to 10% fs with a test-retest reliability of 5% fs.