Perception of Speech in Context by Listeners With Healthy and Impaired Hearing
NCT Number: NCT06465979
Status: RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Hearing|Hearing Loss
Interventions: BEHAVIORAL: Speech Manipulation
Sponsor: University of Louisville
Collaborators: National Institute on Deafness and Other Communication Disorders (NIDCD)
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 680
Study Design: Allocation: NA|Intervention Model: SINGLE_GROUP|Masking: NONE|Primary Purpose: BASIC_SCIENCE
Start Date: 2023-09-18
Completion Date: 2027-07-31
Locations: University of Louisville, Louisville, Kentucky, 40292, United States|University of Minnesota, Minneapolis, Minnesota, 55455, United States

Summary:
Recognition of speech sounds is accomplished through the use of adjacent sounds in time, in what is termed acoustic context. The frequency and temporal properties of these contextual sounds play a large role in recognition of human speech. Historically, most research on both speech perception and sound perception in general examine sounds out-of-context, or presented individually. Further, these studies have been conducted independently of each other with little connection across labs, across sounds, etc. These approaches slow the progress in understanding how listeners with hearing difficulties use context to recognize speech and how their hearing aids and/or cochlear implants might be modified to improve their perception. This research has three main goals. First, the investigators predict that performance in speech sound recognition experiments will be related when testing the same speech frequencies or the same moments in time, but that performance will not be related in further comparisons across speech frequencies or at different moments in time. Second, the investigators predict that adding background noise will make this contextual speech perception more difficult, and that these difficulties will be more severe for listeners with hearing loss. Third, the investigators predict that cochlear implant users will also use surrounding sounds in their speech recognition, but with key differences than healthy-hearing listeners owing to the sound processing done by their implants. In tandem with these goals, the investigators will use computer models to simulate how neurons respond to speech sounds individually and when surrounded by other sounds.

Primary Outcome Measures: Speech categorization, The participant sits inside a double-walled sound booth. They are seated at a table that contains a computer monitor and a mouse. A single utterance is played over headphones or through a loudspeaker directly in front, and the participant indicates what they thought the utterance was by selecting among various options on the screen using the mouse. During a single block of trials there are between 60 and 160 sounds, depending on the exact experiment. Ordering of stimuli within the block is randomized. That testing block may be repeated multiple times so that the proportion of responses for each sound-response pair can be estimated reliably and precisely. Completion and advancement of trials is at the participant's own pace. Each testing block takes between 4 and 15 minutes., "Post-treatment" where "treatment" is the systematic manipulation of speech sounds. Speech categorization will be evaluated during the main part of the testing. Outcomes will be assessed and data reported through study completion, an average of 1 year
Secondary Outcome Measures: Speech recognition, The participant sits inside a double-walled sound booth. They are seated at a table that contains a computer monitor and a mouse. Recorded sentences are played over headphones or through a loudspeaker directly in front, and the participant indicates what they thought the utterance was by typing their response or repeating the sentence aloud. During a single block of trials there are 50 words. Ordering of words within the block is randomized. Completion and advancement of trials is at the participant's own pace. Each testing block takes between 6 and 15 minutes., "Post-treatment" where "treatment" is the systematic manipulation of speech sounds. Word recognition will be evaluated during the main part of the testing. Outcomes will be assessed and data reported through study completion, an average of 1 year|Audiometric threshold testing, The participant sits inside a double-walled sound booth. Under headphones, they listen for soft tones played by an audiometer. The experimenter controls the timing, frequency and intensity of those tones to find the lowest sound intensity where the participant can detect the tone. Thresholds for sound detection are recorded for octave frequencies between 250 Hz and 8000 Hz., Baseline