Dr. Matthias Latzel, Stäfa (Switzerland)
Video 6 
2017
“Speech intelligibility in a dual-task paradigm using hearing instruments and adaptive digital wireless microphone technology”
External microphones are part of a complete hearing solution as they facilitate intelligibility of distant talkers. However, this combination makes intelligibility in the near field difficult as only the omni-directional microphone is active in the hearing aid. A system has been developed that allows the use of the directional microphone in combination with an external microphone. The study investigating this system is presented here.
In the study, speech tests have been conducted using a dual-task paradigm. Primary task: presentation of OLSA (Oldenburg sentence test) sentences in diffuse noise; task: select recognised name. Secondary task: parallel presentation of GÖSA (Göttingen sentence test) sentences; task: repeat all the words recognised. The primary task was presented via a loudspeaker in the far field, the secondary task via a loudspeaker in the near field, and vice versa.
Test conditions:
1. Hearing aids in “dir” mode without external microphone
2. Hearing aids in “omni” mode with external microphone
3. Hearing aids in “dir” mode with external microphone
microphoneMeasurements showed benefit from the external microphone for subjects with severe hearing loss. Analysing both tasks together revealed a positive effect from the directional microphone, which was confirmed in subjective paired comparisons.