Meeting Topic: Can hearing-aid users benefit from enhanced pinna cues for sound localisation?
Moderator Name: Piotr Majdak
Speaker Name: Søren Laugesen, PhD. Eriksholm Research Centre, Rørtangvej 20, 3070 Snekkersten, Denmark, www.eriksholm.com
Meeting Location: Acoustics Research Institute, Austrian Academy of Sciences, Wohllebengasse 12-14, Vienna, Austria
The spatial acoustic cues provided by the pinna are direction-dependent spectral colourations at high frequencies. These cues are important for up/down and front/back localisation, and possibly also for auditory stream segregation. The localisation benefit has been shown in many studies, in particular, with normal-hearing listeners. For people with hearing loss, however, it can be argued that natural pinna cues are imperceptible due to reduced frequency selectivity in the impaired ear. For hearing-aid users, pinna cues may be even inaccessible due to limitations in audio bandwidth, or the placement of the hearing aid's microphones above the ear.
A few years ago a study was conducted to examine the potential benefit of providing hearing-aid users with pinna cues, by placing the microphone at the entrance of the ear canal and by ensuring sufficient amplification at high frequencies. The results indicated that only a minority achieved consistent benefit from pinna cues. This has recently lead to the idea of providing hearing-aid users with 'enhanced' pinna cues by mimicking an over-sized pinna, which introduces its spectral colouration at lower frequencies because of its larger size.