Effect of auditory feedback on speech intelligibility of adults with cochlear implants

Auditory feedback (AF) contributes to speech intelligibility (SI) which is vital in social interactions to examine AF effect on SI of adults with cochlear implant (CI). The relationship between age of CI implantation and AF on SI was examined as well.

Twenty native Hebrew speaker pre-lingual adults with a hearing loss using CIs from ages 2 to 19 years. Participants were recorded reading excerpts from a book and word lists from MIDBAR test in two situations-with and without using their CIs. Sixteen judges listened to the recordings and rated the speech characteristics of the participants reading the excerpts using an adapted version of Speech Intelligibility Test and Intelligibility Questionnaire for Teachers.

Significant differences were found between the SI of words of those who received CI before and after 3 years. AF effect was found only for the older implantation group. The questionnaire indicates good reliability among all the speech characteristics. The speech characteristics most affected by the AF are the disruption of consonants followed by the varied degrees of intonation precision and nasality.

AF affects speech characteristics differently and is vital to SI. The use of the adapted version of Speech Intelligibility Test and Intelligibility Questionnaire for Teachers can be used clinically to assess SI and rehabilitation of young adults with CI. AF accessed at a younger age decreases the dependency on AF in later years.