Temporal modulation transfer function for efficient assessment of auditory temporal resolution.

Two common measures of auditory temporal resolution are the temporal modulation transfer function (TMTF) and the gap detection threshold (GDT). The current study addresses the lack of efficient psychophysical procedures for collecting TMTFs and the lack of literature on the comparisons of TMTF and GDT. Two procedures for efficient measurements of the TMTF are proposed: (1) A Bayesian procedure that adaptively chooses the stimulus modulation rate and depth to maximize the information gain from each trial and (2) a procedure that reduces the data collection to two adaptive staircase tracks. Results from experiments I and II showed that, for broadband carriers, these approaches provided similar results compared to TMTFs measured using traditional methods despite taking less than 10 min for data collection. Using these efficient procedures, TMTFs were measured from a large number of naive listeners and were compared to the gap detection thresholds collected from the same ears in experiment III. Results showed that the sensitivity parameter estimated from the TMTF measurements correlated well with the GDTs, whereas the cutoff rate is either uncorrelated or positively correlated with the gap detection threshold. These results suggest caution in interpreting a lower GDT as evidence for less sluggish temporal processing.