Correlation of speech intelligibility and spectral resolutional in patients after cochlear implantation

One of the most frequent complaints from patients with bilateral sensorineural deafness after cochlear implantation (CI) is the deterioration of speech intelligibility in a noisy environment. International researches have proven a correlation between speech intelligibility and spectral hearing resolution (HRS) in normal hearing subjects. The aim of the study was to determine the correlation of speech intelligibility in noise in CI users with HRS. Materials and methods of research: to estimate the speech intelligibility in noise the international Oldenburg test RUMatrix was used, to determine the HRS – SMRT test (spectrum-temporarily modulated riple test) was applied. The control group included 15 subjects without hearing impairment examined in the original version of the tests and using a vocoder. The study included 22 patients after CI implanted with «Cochlear» CI systems with experience of using CI system for more than 3 years. Results: The study performed in the control group revealed a high correlation of SMRT test and RUMatrix test results. The group of patients after CI consisted of pre- and postlingvally deafened patients. A correlation between speech intelligibility in noise and HRS (R2 = 0.55) was found in patients with postlingual deafness, and no correlation was found in the prelingual group (R2 = 0.03). Conclusions: The SMRT test correlates with speech audiometry data which allows to recommend its use to assess patients rehabilitation outcomes regardless of the level of speech development.