Multi-microphone technology for severe-to-profound hearing loss

In this study the potential benefit of hearing instruments with multi-microphone technology was investigated in laboratory and in field tests for users with severe-to-profound hearing loss. Twenty-one experienced hearing aid users were fitted with high-power multi-microphone hearing instruments (Phonak PowerZoom P4 AZ). The following evaluations were performed: (i) adaptive speech test (SRT for HSM sentence test) in quiet and in noise with their own instrument and the test instrument in the omnidirectional (basic program) and directional mode (party noise profound+zoom algorithm). (ii) Paired comparisons of loudness, sound quality and speech intelligibility for both the omni and zoom program. (iii) Questionnaires on satisfaction and self-assessment of communication in different listening conditions (Oldenburg Inventory). Only 10 subjects achieved 50% correct (SRT) on the sentence test in noise (speech 0 degrees/noise 180 degrees) with both their own instrument and the test instrument in the omnidirectional mode. However, 15 subjects succeeded in the SRT measurement in the directional mode. The average SRT improvement of the directional over the omnidirectional mode was 13.7 dB. Loudness was judged 'medium loud' for both listening programs. Sound quality and intelligibility were rated significantly better for the zoom program. Compared to their own instrument users' satisfaction with the test instrument was significantly higher, especially in noisy listening situations.