Electric-acoustic Stimulation in Contralateral Normal Hearing

Patients with residual low-frequency hearing who are able to use electrical acoustic stimulation (EAS) after cochlear implant (CI) surgery achieve better speech comprehension, especially in noisy environments, compared to CI-only users. Little experience is available for patients who use EAS with normal hearing of the other side. The aim of this study was to investigate the postoperative hearing performance of this group of patients.

Between 09/2011 and 09/2020, 16 patients with normal hearing in one side and indication for EAS in the other side were implanted following a hearing preservation procedure. Pre- and postoperative pure tone audiometry was performed. In four EAS users, speech comprehension in noise was assessed in three different noise situations using Oldenburg sentence testing (OLSA). The results of the speech tests in EAS use (best-aided) were compared with the normal hearing ear (unilateral) and a control group.

The mean value of the low frequencies (125, 250, 500 Hz) was 30 dB (n=16) preoperatively, worsened significantly to 48 dB (n=14) one month postoperatively and was also 48 dB (n=14) on the last available test (6-100 months postop). With spatial separation of speech and noise, speech comprehension with EAS improved by 0.6 to 4.2 dB. Only a slight improvement ( < 1 dB) was achieved in diffuse noise. Depending on the noise situation, EAS speech understanding was between 3.8 and 7 dB worse than that of the normal hearing control group.

Even in patients with normal hearing on one side and low frequency residual hearing on the other, useful hearing preservation is achieved and EAS can improve speech understanding in noise. Thus, even with unilateral normal hearing, EAS fitting is promising.

Poster-PDF A-1142.pdf

Conflict of interest

Der Erstautor gibt keinen Interessenskonflikt an.

Publication History

Article published online:
13 May 2021