Perception of Speech in Context by Listeners With Healthy and Impaired Hearing
Marquette University
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.
Description
Participants in this study listen to speech played at a comfortable volume and respond by indicating what they heard, either in open-ended form or by choosing among a set of options displayed on a computer. They are seated inside a sound booth and complete the task at their own pace, with little intervention needed from the experimenter. Upon arrival at the lab, participants are given a brief description of the topic of the research (how earlier sounds influence our perception of later speech sounds) and are presented with a detailed informed consent form. Their demographic information is coll…
Eligibility
- Age range
- 18–65 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Be able to recognize spoken words in English * Be a competent speaker of north American English * Be an adult between the age of 18 to 65 years * Have normal audiometric thresholds below 25 decibels hearing loss (dB HL) at frequencies between 250 and 8000 Hz OR have audiometric thresholds not exceeding 40 dB HL at frequencies between 250 and 8000 Hz OR have audiometric thresholds not exceeding 55 dB HL at frequencies between 250 and 8000 Hz OR use a cochlear implant * Lack language-learning or other cognitive disabilities Exclusion Criteria: * Inability to recognize sp…
Interventions
- BehavioralSpeech Manipulation
The acoustic properties of speech sounds will be modified in two main ways. The first way is to introduce gradual changes to the perceived articulation of the target speech sound, such as changing from "sh" to "s" by various types of signal processing and filtering. The second type of change is to modify acoustic properties of the sounds that immediately precede the target speech sound, such as changing the speaking rate or its frequencies composition.
Locations (2)
- University of MinnesotaMinneapolis, Minnesota
- Marquette UniversityMilwaukee, Wisconsin