Viji Easwar, PhD

Position title: Assistant Professor, Communication Sciences and Disorders

PhD, The University of Western Ontario
Assistant Professor, Communication Sciences and Disorders

Contact Information

Waisman Center
1500 Highland Avenue
Room 541
Madison, WI 53705
608.263.5641
veaswar@wisc.edu
Child Hearing Lab

Research Statement

My research focuses on auditory development in children with and without hearing loss. In particular, I am interested in investigating the effects of age, auditory deprivation, and hearing prostheses like hearing aids or cochlear implants on how sounds, particularly speech stimuli, are encoded by the auditory system using electroencephalography (EEG) techniques. In addition to studying auditory development, my research interests include investigating factors that contribute to between-subject variability in EEG measures evoked by sound. Of particular interest is the speech-evoked envelope following response. The overall goal of my research program is to develop evidence that can help inform intervention strategies in children with hearing loss and extend the use of EEG techniques to clinical practice to help clinicians (audiologists) evaluate intervention outcomes in children.

I currently direct the Child Hearing Lab, or in short, the Chear lab. We collaborate closely with the Efferent Systems Lab directed by Dr. Sriram Boothalingam.

Selected Publications

Easwar, V., Boothalingam, S., & Flaherty, R. (2021). Fundamental frequency-dependent changes in vowel-evoked envelope following responses. Hearing research, 408, 108297. https://doi.org/10.1016/j.heares.2021.108297
Easwar, V., Birstler, J., Harrison, A., Scollie, S., & Purcell, D. (2021). The Influence of Sensation Level on Speech-Evoked Envelope Following Responses. Ear and hearing, 10.1097/AUD.0000000000001078. Advance online publication. https://doi.org/10.1097/AUD.0000000000001078
Urichuk, M., Easwar, V., & Purcell, D. (2021). Montage-related Variability in the Characteristics of Envelope Following Responses. Ear and hearing, 42(5), 1436–1440. https://doi.org/10.1097/AUD.0000000000001018
Easwar, V., Bridgwater, E., & Purcell, D. (2021). The Influence of Vowel Identity, Vowel Production Variability, and Consonant Environment on Envelope Following Responses. Ear and hearing, 42(3), 662–672. https://doi.org/10.1097/AUD.0000000000000966
Easwar, V., Scollie, S., Lasarev, M., Urichuk, M., Aiken, S. J., & Purcell, D. W. (2021). Characteristics of Speech-Evoked Envelope Following Responses in Infancy. Trends in hearing, 25, 23312165211004331. https://doi.org/10.1177/23312165211004331
Easwar, V., Birstler, J., Harrison, A., Scollie, S., & Purcell, D. (2020). The Accuracy of Envelope Following Responses in Predicting Speech Audibility. Ear and hearing, 41(6), 1732–1746. https://doi.org/10.1097/AUD.0000000000000892
Easwar V, Scollie S, Aiken S, Purcell D. (2020). Test-Retest Variability in the Characteristics of Envelope Following Responses Evoked by Speech Stimuli. Ear and Hearing, 41(1):150-164. doi: 10.1097/AUD.0000000000000739.
Easwar V, Scollie S, Purcell D. (2019). Investigating potential interactions between envelope following responses elicited simultaneously by different vowel formants. Hearing Research, 380:35-45. doi: 10.1016/j.heares.2019.05.005.
Easwar V, Sanfilippo J, Papsin B, Gordon K. (2018) Impact of consistency in daily device use on speech perception abilities in children with cochlear implants: Datalogging evidence. Journal of the American Academy of Audiology, 29(9):835-846. doi: 10.3766/jaaa.17051.
Easwar V, Yamazaki H, Deighton M, Papsin B, Gordon K. (2017) Simultaneous bilateral cochlear implants: Developmental advances do not yet achieve normal cortical processing. Brain and Behavior. 28;7(4):e00638. doi: 10.1002/brb3.638.
Easwar V, Yamazaki H, Deighton M, Papsin B, Gordon K. (2017) Cortical Representation of Interaural Time Difference Is Impaired by Deafness in Development: Evidence from Children with Early Long-term Access to Sound through Bilateral Cochlear Implants Provided Simultaneously. Journal of Neuroscience. 1;37(9):2349-2361. doi: 10.1523/JNEUROSCI.2538-16.2017.
Easwar V, Purcell DW, Aiken SJ, Parsa V, Scollie SD. (2015) Evaluation of Speech-Evoked Envelope Following Responses as an Objective Aided Outcome Measure: Effect of Stimulus Level, Bandwidth, and Amplification in Adults With Hearing Loss. Ear and Hearing. 36(6):635-52. doi: 10.1097/AUD.0000000000000199.
Easwar V, Purcell DW, Aiken SJ, Parsa V, Scollie SD. (2015) Effect of Stimulus Level and Bandwidth on Speech-Evoked Envelope Following Responses in Adults With Normal Hearing. Ear and hearing, 36(6), 619–634. https://doi.org/10.1097/AUD.0000000000000188
Easwar V, Beamish L, Aiken S, Choi JM, Scollie S, Purcell D. (2015) Sensitivity of envelope following responses to vowel polarity. Hear Res. 320:38-50. doi: 10.1016/j.heares.2014.11.008.