Bimodal Stimulation with Cochlear Implant and Hearing Aid in Cases of Highly Asymmetrical Hearing Loss

Bimodal stimulation is a possible treatment for asymmetrical hearing loss, wherein 1 ear is stimulated with a cochlear implant and the other is stimulated with a hearing aid. This emerging indication has gained significance over the last few years. However, little research has been conducted regarding the performance in different types of asymmetric Hearing loss. This study seeks to prove the bilateral-binaural advantage in a group of patients treated with bimodal stimulation (cochlear implant and hearing aid), with different degrees of hearing loss in their best ear.

In total, 31 patients were recruited for the study. They were divided into 3 groups on the basis of the ear with the hearing aid: Group A, pure tone average (PTA) between 41 and 70 dB HL; Group B, PTA between 71 and 80 dB HL; and Group C, PTA between 81 and 90 dB HL. The performance in PTA and disyllabic word recognition were analyzed separately in each ear and then bimodally. The minimum follow-up period was 2 years.

There were statistically significant differences between bimodal and monaural conditions both in PTA and in disyllabic word recognition. The better the residual hearing in the ear with the hearing aid, the greater were the benefits obtained with bilateralism-binaurality.

Bimodal stimulation provides better results than any monaural hearing mode, regardless of whether it involves the use of a hearing aid alone or a cochlear implant alone.