Contribution

Technical survey of a multi-channel loudspeaker system to generate realistic sound fields for hearing aid evaluation

Authors

* Presenting author
Day / Time: 18.03.2025, 15:20-16:00
Room: Hall E, Poster Island F
Typ: Poster
Session: Methods for Technical and Perceptual Evaluations of Hearing Devices (Poster Island F)
Information: The posters will be exhibited in Hall E north from Tuesday to Thursday, sorted by thematic context in the poster island indicated in the session title. The poster session at the specified time offers the opportunity to enter into discussion with the authors.
Abstract: Hearing aid evaluations are typically conducted in laboratories with basic acoustic setups, often with few loudspeakers. However, these controlled soundscapes do not usually reflect the complex situations that hearing aid users encounter everyday. This discrepancy can be addressed by using multi-channel loudspeaker systems to generate realistic, ecologically valid acoustic scenes in a physically correct manner. This contribution presents the technical evaluation of a loudspeaker system installed at the University of Applied Sciences Lübeck.The loudspeaker system includes 65 passive coaxial loudspeakers arranged spherically with a radius of 1.5 m and 4 active subwoofers. The loudspeakers’ transfer functions, equalized with parametric IIR filters, achieved a flat frequency response with a maximum of 3 dB deviation between 100 Hz and 10 kHz. The consistent directional characteristics allow for a reproduction area within 10.5 cm radius at a 1 dB tolerance in the center of the array. The resulting sweet spot using 7th-order Ambisonics encompasses a radius of 12.5 cm, maintaining a 3 dB level tolerance up to 4 kHz.Measurements confirm that the loudspeaker system enables an accurate physical reproduction of typical everyday sound environments. The size of the sweet spot also provides enough room for positioning participants during hearing aid experiments.