Clarity in Motion Phase-1 Perceptual Study of Speech Intelligibility

Participants received a bilateral pure-tone hearing screen administered by the research team. All potential participants who failed the hearing screen were provided with information about its meaning and referral for further audiological testing. Participants who passed the hearing screen and other inclusion criteria were divided into 6 groups, each of which were presented with 144 stimuli equally distributed among processing conditions. Listeners choose a comfortable listening level using supplied headphones and were able to control the rate of presentation. Following a short practice session, listeners were be asked to transcribe each target sentence. The intelligibility of each stimulus was estimated by determining the mean percentage of content words correctly transcribed. After transcription, listeners were asked for two qualitative judgments: (1) the "clarity" of the stimulus, and (2) the "listening effort" involved. The quality of each stimulus was estimated by the median quality judgment, and the effort likewise. Listening sessions were located in a quiet room and presentation was controlled by the Superlab presentation software program. The Stimuli consisted of audio recordings of target spondaic words embedded in a carrier sentence produced by a male and a female native speaker of American English recorded under quiet conditions. Each stimulus presented to the listeners for identification was either unmasked pristine speech or speech that had been processed in one of five ways with different mixtures of noise and sensor movement. The latter are identified as QoS Levels 1-5. Collectively, the estimates of word intelligibility, clarity, and listening effort under the different conditions shed light on the effectiveness with which the tested algorithm preserves listener intelligibility with acceptable effort and quality.