University of South Florida
Understanding speech in restaurants and other noisy environments is the most common complaint from the more than 60 million Americans with hearing impairment. Succeeding in such environments requires a listener to first segregate sound sources and then selectively attend to the source of interest. This study examines how individual auditory spatial cues (interaural time differences and interaural level differences) support spatial selective attention, the cortical processes that underlie this ability, and how these processes are modulated by task demands. Participants with normal hearing and participants who use bilateral cochlear implants will perform listening tasks while brain and physiological responses are recorded (electroencephalography, functional near-infrared spectroscopy, pupillometry, and, for normal-hearing participants only, functional magnetic resonance imaging). The findings will provide new insights into the mechanisms of spatial selective attention and help guide clinical solutions for cochlear implant users, individuals with hearing impairment more generally, and older normal-hearing adults who have difficulty understanding speech in noisy environments.
This study will examine the contributions of spatial cues (interaural level differences and interaural time differences) and task demands on spatial selective attention. Aim 1 will simultaneously collect functional near infrared spectroscopy (fNIRS), electroencephalography (EEG), pupillometry, and behavioral data in normal-hearing (NH) participants, while they perform tasks designed to probe various aspects of spatial selective attention. We will make every effort to include as many Aim 1 participants in Aim 2 as possible. Aim 2 will record functional magnetic resonance imaging (fMRI) during t…
Inclusion Criteria: * Adults with normal hearing, confirmed by audiometric assessment (thresholds within 20 dB HL of normal through 8 kHz), OR adults with bilateral cochlear implants who have used their implants for at least one year * Native speakers of American English * Normal or corrected-to-normal vision Exclusion Criteria: * Known neurological disorders * For fMRI sessions (normal-hearing participants only): contraindications to MRI scanning; cochlear implant users do not complete MRI sessions
Participants in this arm are recruited from a population who have existing bilateral cochlear implants. The implants are the participants' own clinical devices, used as clinically programmed; no investigational device or modification is provided by the study. Auditory attention tasks are presented with manipulated spatial cues (interaural time differences, interaural level differences, or HRTFs).
Control group recruited from the normal hearing population. Participants perform the same auditory attention tasks with manipulated spatial cues (interaural time differences, interaural level differences, or HRTFs) under EEG/fNIRS/pupillometry and fMRI.