Research
Overview
In the SPAN Lab, we investigate various aspects of auditory processing in adults of
all ages to gain a better understanding of underlying mechanisms that contribute to
speech perception in difficult listening situations. We are also working to inform
treatment strategies that may help to improve these hearing outcomes in those with
hearing loss, tinnitus, or cochlear implants.
To these endeavors, we utilize research techniques across different domains that include
audiological testing (audiograms, tympanograms, otoacoustic emissions, auditory brainstem
responses), behavioral testing (psychophysical, speech intelligibility, cognitive),
and electrophysiological testing (frequency following response, mismatch negativity,
P300).
The importance of F0 in auditory processing
The fundamental frequency (F0) is perceived as pitch and is a primary cue that helps listeners to identify different talkers. In noisy settings, this pitch differentiation helps listeners to maintain attention on a particular talker’s voice while ignoring other competing sounds. F0, combined with other talker identity cues, also aid listeners with being able to adapt to speech sounds that are different from what listeners are accustomed to in their daily lives, such as non-native speech. These F0-dependent processes become more difficult when listeners have limited access to this cue. Our lab is trying to further elucidate the role of F0 in these contexts in those with hearing loss, tinnitus, or cochlear implants.
the role of nicotinic acetylcholine receptors in auditory processing
Nicotinic acetylcholine receptors (nAChRs) are found throughout the auditory system, including in cortex, brainstem, and the cochlea. These receptors are crucial for various auditory processes including modulation of hair cell function in the cochlea, synaptic transmission along the auditory pathway, enhancing higher order auditory processing and attention, and contributing to brain plasticity needed for auditory adaptation. Much of what we know about these receptors stems from research in animal models. Our lab is interested in utilizing pharmacological approaches to translate these findings in humans and assessing how activation of these receptors can improve auditory processing for pathological hearing.
Effects of Cognition on Auditory Processing
The interplay between cognition and auditory function is complex, occurring across multiple levels including attention, working memory, perceptual organization, top-down processing, and adaptation. Even mild cognitive impairment can disrupt these processes. Our goal is to deepen our understanding of how cognition and auditory function interact and explore whether enhancing specific cognitive components through targeted treatments can also improve related aspects of auditory processing.