Hearing loss classification by degree, configuration and relationship with amplified Speech Intelligibility Index (SII)

Abstract

Purpose: To establish the relationship between speech intelligibility index (SII) values generated at the verification of hearing aids programmed according to DSLm [i/o] v5 prescription rule and a proposed individual classification that considers the combination of hearing loss degree and configuration. Methods: Forty-one children aged between 4 and 80 months were selected, totaling 78 ears for analysis. We considered hearing thresholds at the frequencies of 250, 500, 1000, 2000 and 4000 Hz; and analyzed values of the Speech Intelligibility Index (SII) for the input signal of 65 dB SPL obtained during the verification of hearing aids using the equipment Verifit®Audioscan. Results: Hearing losses were classified into five homogeneous groups regarding audiometric degree and configuration. The groups were heterogeneous when compared to each other. From the groups, three ranges of SII values were determined. Equations were developed for classification of hearing loss according to groups and for determination of the adjusted SII values. Conclusion: The SII value is a useful indicator of audibility for speech sounds in different characteristics of hearing losses, and can guide observations of auditory skills. The SII has stronger relationship with the association of the audiometric degree and configuration when compared with degree of hearing loss alone.