Study of SelfFit Mobile Medical App for Hearing Loss Diagnostics and Hearing Device Fitting / Fine Tuning
Condition: Mild to Moderate Sensorineural Hearing Loss
MeSH terms: Hearing Loss; Deafness; Hearing Loss, Sensorineural
Study type: Interventional

Summary: 
      The purpose of this clinical study is to validate the comparability of prescription formula
      fitting of hearing aids based on full diagnostic audiometry and SelfFit interactive fitting
      of hearing aids based on hearing loss screening (mild to moderate hearing losses) using
      in-situ audiometry, provided and executed through the mobile medical app.
    

Detailed description: 
      The technology utilized within the mobile medical App is partially described in the US patent
      application US2011/0002490A1. The app is to be used in combination with a hearing aid to
      deliver the output and targets accurate individual acoustical amplification for effective
      compensation of a users hearing loss.

      The electronic circuitry incorporating the digital signal processing algorithms - dynamic
      range compression, noise reduction - is providing the acoustical amplification according to
      parameters (acoustical gain, compression ratio, time constants) calculated through the App on
      base of in-situ hearing loss diagnostics (pure tone audiometry, loudness scaling). Within the
      study, amplification parameters will be transmitted to the prototyped device through a
      prototyped audio streaming box.

      Individual audiogram represents hearing thresholds (softest audible sounds) at different
      frequencies. At least two test frequencies are used involving one in the lower region of
      device's bandwidth (such as 750 Hz) and one in the higher region of the device's bandwidth
      (such as 2 kHz). Hearing thresholds are assessed by presenting pure tones of different known
      levels (SPL) to the user and the thresholds for each of the test frequencies are determined
      according to the user response to a verbally formulated question (how many tones did you
      hear?) and multiple choice answer buttons (0, 1, or 2).

      Second hearing loss characteristic obtained by the app. is the personal loudness scaling. By
      presenting a band-limited noise stimuli and collecting the user response about perceived
      loudness level Medical Mobile App calculates dynamic range of users hearing at given
      frequency.

      The calculation of optimal amplification parameters is performed by App using a proprietary
      "fitting formula" derived from scientific data.

      Final adjustment of amplification parameters called fine tuning is performed while presenting
      the user with realistic acoustical environment during operation of the hearing device. Fine
      tuning relates to slight changes of the parameters initially obtained by the "fitting
      formula". The acoustical signals are presented using audio streaming through the hearing aid.
      In particular the presented signals include "speech in quiet" and "speech in background
      noise". Presented speech signal is composed from two or more sources that are processed with
      different signal processing parameters. During the presentation of the speech signal App
      presents the speech source visually as two or more speakers. The user is asked to provide his
      listening preference by choosing the preferred speaker. The signal processing parameters
      relating to the preferred sound are used for final adjustment of hearing device.
    

Intervention name(s): SelfFit adjusted hearing device
Intervention type(s): Device
Intervention description(s): Comparison of threshold measurements through in-situ audiometry with full diagnostic audiometry; Comparison of First-Fit based on SelfFit-formula with conventional fitting formula NAL-NL1 (IG-measurements; Speech intelligibility with First fit of SelfFit; Speech intelligibility with Final fit of SelfFit; Comparison of fine tuning through SelfFit (Final fit) with First fit; Comparison of Final fit with Traditional fit (conventional fitted hearing aid of the test person)
Other intervention name(s): User-fitted hearing device; hearing device fitting software; home-fitting tool for hearing devices
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Audiology; hearing loss; hearing healthcare; mobile app; hearing aid fitting; audiometry; audiogram