A simplified measurement method of TMTF for hearing-impaired listeners

It is difficult to understand speech for listeners with reduced temporal resolution. To measure the auditory index of temporal resolution in clinical diagnosis, a novel measurement method was proposed. It is called a simplified measurement method of temporal modulation transfer function (S-TMTF). This method is based on measurement of temporal modulation transfer function (TMTF). The novelty of S-TMTF lies in the use of only two thresholds for estimation of peak sensitivity and 3-dB cutoff frequency. One is a threshold of modulation depth and the other is a threshold of modulation frequency. In this study, to evaluate the practicability and accuracy of peak sensitivity and 3-dB cutoff frequency, both S-TMTF and TMTF were measured for normal-hearing and hearing-impaired subjects. Results of S- TMTF were significantly correlated with that of TMTF and the measurement time of S-TMTF could be shortened to one fourth of the time for TMTF. Furthermore, the measurement time will be shortened by using the method of limits. S-TMTF would be applied for clinical diagnosis of hearing impairment.