Audiovisual Processing Skills Before Cochlear Implantation Predict Postoperative Speech Recognition in Adults
Authors: Moberly Aaron C. , Pisoni David B. , Tamati Terrin N. 
Published: December 2023

Objectives:
Adults with hearing loss (HL) demonstrate greater benefits of adding visual cues to auditory cues (i.e., “visual enhancement” [VE]) during recognition of speech presented in a combined audiovisual (AV) fashion when compared with normal-hearing peers. For patients with moderate-to-profound sensorineural HL who receive cochlear implants (CIs), it is unclear whether the restoration of audibility results in a decrease in the VE provided by visual cues during AV speech recognition. Moreover, it is unclear whether increased VE during the experience of HL before CI is beneficial or maladaptive to ultimate speech recognition abilities after implantation. It is conceivable that greater VE before implantation contributes to the enormous variability in speech recognition outcomes demonstrated among patients with CIs. This study took a longitudinal approach to test two hypotheses: (H1) Adult listeners with HL who receive CIs would demonstrate a decrease in VE after implantation; and (H2) The magnitude of pre-CI VE would predict post-CI auditory-only speech recognition abilities 6 months after implantation, with the direction of that relation supporting a beneficial, redundant, or maladaptive effect on outcomes.

Design:
Data were collected from 30 adults at two time points: immediately before CI surgery and 6 months after device activation. Pre-CI speech recognition performance was measured in auditory-only (A-only), visual-only, and combined AV fashion for City University of New York (CUNY) sentences. Scores of VE during AV sentence recognition were computed. At 6 months after CI activation, participants were again tested on CUNY sentence recognition in the same conditions as pre-CI. H1 was tested by comparing post- versus pre-CI VE scores. At 6 months of CI use, additional open-set speech recognition measures were also obtained in the A-only condition, including isolated words, words in meaningful AzBio sentences, and words in AzBio sentences in multitalker babble. To test H2, correlation analyses were performed to assess the relation between post-CI A-only speech recognition scores and pre-CI VE scores.

Results:
Inconsistent with H1, after CI, participants did not demonstrate a significant decrease in VE scores. Consistent with H2, preoperative VE scores positively predicted postoperative scores of A-only sentence recognition for both sentences in quiet and in babble (rho = 0.40 to 0.45, p < 0.05), supporting a beneficial effect of pre-CI VE on post-CI auditory outcomes. Pre-CI VE was not significantly related to post-CI isolated word recognition. The raw pre-CI CUNY AV scores also predicted post-CI A-only speech recognition scores to a similar degree as VE scores.

Conclusions:
After implantation, CI users do not demonstrate a decrease in VE from before surgery. The degree of VE during AV speech recognition before CI positively predicts A-only sentence recognition outcomes after implantation, suggesting the potential value of AV testing of CI patients preoperatively to help predict and set expectations for postoperative outcomes.