ABSTRACT
Purpose
Develop a test to evaluate frequency compression by identifying and applying fricative phonemes.
Methods
A speech material was composed of 24 monosyllabic words, containing the phonemes /s, z, f, v, ∫, 3/. Eight subjects recorded words, for a total sample of 192 recordings. Low-pass filters were applied to words with cutoff points values of 1,5 kHz; 2 kHz e 3 kHz, in order to prevent sound detection in the filtered frequency bands, simulating hearing loss at high frequencies. The test was applied to ten normal hearing individuals, who had to listen to the word and identify it on a computer screen. Twelve response options were offered, fixing the vowel and varying the initial fricative phoneme and the presence of the final fricative /s/. The test consisted of 384 word repetitions, 192 with frequency compression. Responses were computed and compared using statistical tests.
Results
The identification of the phonemes was favored by the increase of the cutoff frequency, except in 3 kHz. There was improvement in the identification of fricative phonemes /∫, 3/ with the use of frequency compression, however, for the other assessed phonemes (/f, v/ e /s, z/) no differences were found.
Conclusion
The identification test of fricative phonemes was efficient and reliable. For the cutoff frequencies in 1,5 kHz e 2 kHz, the frequency compression was effective for the identification of the fricative phonemes /∫, 3/, however the identification of /s/ at the end was affected by the algorithm.
Hearing loss, High-frequency; Speech discrimination tests; Hearing aids; Hearing loss, Sensorineural; Speech perception