Relations between psychophysical data and speech perception for hearing-impaired subjects. II.

Twenty-one sensorineurally hearing-impaired adolescents were studied with an extensive battery of tone-perception, phoneme-perception, and speech-perception tests. Tests on loudness perception, frequency selectivity, and temporal resolution at the test frequencies of 500, 1000, and 2000 Hz were included. The mean values and the gradient across frequencies were used in further analysis. Phoneme-perception data were gathered by means of similarity judgments and phonemic confusions. Speech-reception thresholds were determined in quiet and in noise for unfiltered speech material, and with additional low-pass and high-pass filtering in noise. The results show that hearing loss for speech is related to both the frequency resolving power and temporal processing by the ear. Phoneme-perception parameters proved to be more related to the filtered-speech thresholds than to the thresholds for unfiltered speech. This finding may indicate that phoneme-perception parameters play only a secondary role, and for that reason their bridging function between tone perception and speech perception is only limited.