School of Communication Science and Disorders Assistant Professor Dr. Yasmeen Hamza’s research, “Representation of fricatives in subcortical model responses: Comparisons with human consonant perception,” was recently published in the Journal of Acoustical Society of America (JASA).

JASA focuses on publishing research that highlights theoretical and experimental results in the subject of audiology. This journal publishes and aids physical scientists, life scientists, engineers, psychologists, physiologists, architects, musicians, and speech communication specialists.

Hamza is the lead author of this research and she worked alongside her co-authors from the University of Rochester– Afagh Farhadi, Douglas M. Schwarz, Joyce M. McDonough, and Laurel H. Carney. Their study investigated modeled neural responses to fricatives (a class of consonant sounds) in the auditory nerve (AN) and inferior colliculus (IC), with the aim of understanding why fricatives are perceived with high accuracy despite their variability in production. A second aim was to investigate the role extended (non-conventional) high frequencies play in the accuracy of perception.

Modeled neuron responses provided better predictions of behavioral accuracies than the stimulus cues, demonstrating that the relationship between physical cues for incoming sounds and neural responses is not straightforward. Additionally, the study provided neural-modeling-based support to the relatively new evidence that higher-frequency acoustic information influences speech intelligibility.

“Future studies that stimulate neural responses of the hearing-impaired ear to fricatives could guide the development of processing strategies that aim at reaching the normal-hearing neural targets. We are currently looking at validating the role of extended frequencies in speech perception and the interaction with cognitive aspects,” Hamza explained.