Speech understanding in noise with an eyeglass hearing aid: asymmetric fitting and the head shadow benefit of anterior microphones.
OBJECTIVE
To test speech understanding in noise using array microphones integrated in an eyeglass device and to test if microphones placed anteriorly at the temple provide better directivity than above the pinna.


METHODS
Sentences were presented from the front and uncorrelated noise from 45, 135, 225 and 315°.


METHODS
Fifteen hearing impaired participants with a significant speech discrimination loss were included, as well as 5 normal hearing listeners.


RESULTS
The device (Varibel) improved speech understanding in noise compared to most conventional directional devices with a directional benefit of 5.3 dB in the asymmetric fit mode, which was not significantly different from the bilateral fully directional mode (6.3 dB). Anterior microphones outperformed microphones at a conventional position above the pinna by 2.6 dB.


CONCLUSIONS
By integrating microphones in an eyeglass frame, a long array can be used resulting in a higher directionality index and improved speech understanding in noise. An asymmetric fit did not significantly reduce performance and can be considered to increase acceptance and environmental awareness. Directional microphones at the temple seemed to profit more from the head shadow than above the pinna, better suppressing noise from behind the listener.
Department of Otorhinolaryngology, Head and Neck Surgery, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. l.mens@kno.umcn.nl
Lucas H M
LH
Mens
D000161:Acoustic Stimulation; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D032882:Comprehension; D012048:Correction of Hearing Impairment / Q000523:psychology; D004867:Equipment Design; D005139:Eyeglasses; D005260:Female; D006310:Hearing Aids; D034381:Hearing Loss / Q000523:psychology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D013017:Sound Localization; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013067:Speech Perception; D013069:Speech Reception Threshold Test; D014159:Transducers