Subjective Evaluation of a Sound Processing Method for Hearing Aids on Auditory Distance Perception

Subjective Evaluation of a Sound Externalization Method in Remote Microphone Systems for Binaural Hearing Aids With Respect to Auditory Distance Perception

Within the course of this study, a signal processing feature has been developed at Ecole Polytechnique Fédérale de Lausanne (EPFL), in collaboration with Sonova AG, in order to enhance the listening experience with remote microphone systems. In particular, the developed feature is supposed to improve the so-called audio-visual fusion, i.e. the fact to perceive the sound as coming from the physical location of the source. One of the main goals of the present study is to evaluate the extent to which this feature reaches that objective.

Subjects fulfilling all of the following inclusion criteria are eligible for the study:

• Willing and able to give written informed consent as documented by signature,
• French-native adult speakers,
• (Preferably) younger than 60 y.o.

For all normal-hearing participants:

- Hearing thresholds lower or equal to 20 dB on both ears, as ensured by a pure-tone audiometry (125 Hz to 8 kHz) conducted at the beginning of the session.

For all hearing-impaired patients:

• Patients of Mr. Philippe Estoppey, private audiologist settled in Lausanne,
• User of bilateral BTE Phonak hearing aids, commercialized after July 2012, with fittings that did not change over the last three months,
• Presenting a severe-to-profound sensorineural hearing loss,
• Presenting a symmetrical hearing loss (no bilateral hearing threshold that differ by more than 20 dB at any audiometric frequency (125 Hz - 4 kHz)).

For HI patients experienced with remote microphone systems:

- Past or present users of FM and/or Roger devices for more than six months.

For other HI patients:

- No past or present experience with FM and/or Roger devices for more than one month.

The presence of any one of the following exclusion criteria will lead to exclusion of the participant:

• Collaborator of the laboratory (LTS2) or student attending the courses of audio and acoustics given by the laboratory staff (EE-348 Electroacoustics, EE-548 Audio Engineering),
• History of chronic or terminal illness, psychiatric disturbance, senile dementia, or cognitive impairment,
• History of strong tinnitus and/or hyperacusis,
• Strong visual impairment after correction with glasses or not,
• History of epilepsy or other reactions associated with the proximity to a screen,
• Motor disability that would disturb their presence at EPFL.