Results of a pilot study with a signal enhancement algorithm for HiRes 120 cochlear implant users

Cochlear implant users still experience severe limitations regarding sound quality, music appreciation, and speech perception in adverse listening situation. To improve hearing in noisy environments, the incorporation of signal enhancement algorithms was initiated.

The study group consisted of 13 postlingually deafened adults using HiRes 120. Participants were fitted with 2 versions of the noise reduction algorithm: a moderate and a strong setting. In an immediate session, the HSM sentence test in speech-shaped noise was administered using the clinical program as well as both noise reduction programs. Participants were asked to try all 3 programs in everyday listening situations at home and provide a rating of sound quality and speech perception via a questionnaire (Abbreviated Profile of Hearing Aid Benefit).

During the fitting, no difficulties were encountered, and all participants accepted the noise reduction programs without any acclimatization. All participants achieved better results with both noise reduction programs in the HSM sentence test in noise compared with the clinical program. Group mean speech perception scores were highly significantly better for the ClearVoice settings compared with the clinical program score. The majority preferred one of the ClearVoice conditions, with 4 participants for the strong and 3 for the moderate setting.

Our results demonstrate a real potential benefit for noise reduction algorithms in cochlear implant processors. Although algorithm parameters were not optimized individually, a significant improvement could still be achieved. Further investigation is required to develop fitting guidelines and achieve parameter optimization.