Factors affecting speech recognition performance in quiet and in noise in adults with cochlear implants.

In the past decade, numerous papers have published on variability in speech recognition in adults with a cochlear implant (CI). Many variables thought to influence the outcome of cochlear implantation have been investigated both in retrospective and prospective studies. In this study, we investigated different biographic, audiologic and electrode position related variables for their relation with speech recognition performance in both quiet and in noise. Participants were 134 adults with post-lingual onset of deafness, with Cochlear CI systems (either with a Contour Advanced or with a Slim Straight electrode) implanted at one single CI center. Biographic factors were: age, level of education and psychological screening questionnaires. Audiologic factors were: duration of hearing loss, and pre-implantation speech recognition scores. The electrode position was determined on a high-resolution CTscan post-implantation, using "Matlab" software. Electrode position variables were: electrode scalar position, electrode insertion angle and wrapping factor (electrode proximity to the modiolus). NVA-wordlists, (55 dB and 70 dB) were used to measure speech recognition scores in quiet at three time-points post-implantation: three months, 12 months and at the time of post-implantation CT-scan. Speech recognition scores in noise were assessed using the digits-innoise (DIN) test at 12 or more months post-implantation. To investigate the influence of biographic, audiologic and electrode position related variables of adult CI patients on speech perception performance in quiet and in noise, we used multivariate linear regression analysis. [ABSTRACT FROM AUTHOR]