Effects of training and using an audio-tactile sensory substitution device on speech-in-noise understanding
Level 3 - non-randomized controlled study
Controlled experimental laboratory study (randomization not specified in abstract)
OpenAlex W4214545628 · doi:10.1038/s41598-022-06855-8
What was done
Researchers evaluated an audio-tactile sensory substitution device that translates low-frequency speech components into fingertip vibrations. Two groups of non-native English speakers completed a single 30-45 minute training session repeating distorted sentences in noise, either with or without concurrent matching vibrotactile stimulation. Participants were evaluated pre- and post-training on Speech Reception Thresholds (SRT) under three conditions: auditory-only, matching audio-tactile vibrations, and non-matching audio-tactile vibrations.
What was found
Both training groups showed comparable mean SRT improvements of 14-16 dB when tested in auditory-only and matching audio-tactile conditions. The number of sentence repetitions required during training was similar between groups, but the mean signal-to-noise ratio during training was significantly lower for audio-tactile training (14.7 ± 8.7 dB) than for auditory-only training (23.9 ± 11.8 dB). Across both pre- and post-training assessments, 70-80% of participants demonstrated a 4-6 dB multisensory benefit when speech was paired with matching vibrations, achieving a post-training SRT of ~2 dB. Non-matching vibrations yielded the smallest training effect and poorest post-training performance.
Why it matters
The findings demonstrate that adult sensory processing can rapidly integrate novel tactile representations of speech to improve speech comprehension in noisy conditions, supporting the potential of low-frequency vibrotactile sensory substitution for auditory rehabilitation and hearing assistance.
Limits
The abstract does not report the total sample size (n), participant demographics beyond non-native English speaker status, or whether group assignment was randomized. Long-term retention was not assessed beyond the immediate 30-45 minute post-training period, and testing was conducted in a controlled laboratory setting with non-native speakers rather than individuals with clinical hearing impairment.
Cited by
- supports Sensory substitution devices that convert sound into patterns of vibration on the skin enable deaf individuals to learn to interpret auditory information.