Mark Hedrick, Ph.D.

See Also: Psychoacoustics Laboratory

Field Specialty

Speech perception, psychophysics

Research Interests

Our research is principally centered on perception of speech by individuals with hearing loss. We are involved in determining what information from the speech signal the listener with hearing loss pays most attention to, and how this may be different from listeners with normal hearing. We are also involved in examining how degraded listening conditions (noise, reverberation) specifically alter listeners’ perception of speech at the phoneme level. We are also involved in investigating the effects of aging and spectral shaping of consonants upon listeners’ perception and neural representation, as well as the effects of nicotine upon perception. We have also examined the effects of auditory training programs.


  • B. S., West Virginia Wesleyan (1983)
  • M. Ed., University of Virginia (1986)
  • Ph.D., Vanderbilt University (1991)

Representative Publications

  • Bahng, J., Hedrick, M., & von Hapsburg, D. (in press). Weighting of static and transition cues in voiceless fricatives and stops in children wearing cochlear implants. Clinical and Experimental Otorhinolaryngology.
  • Hedrick, M., Charles, L., & Street, N. (in press). Vowel perception in listeners with normal hearing and in listeners with hearing loss. Clinical and Experimental Otorhinolaryngology.
  • Hedrick, M., Lee, J.Y., Harkrider, A., & von Hapsburg, D. (2014). Effects of sentence context on phonemic categorization on natural and synthetic consonant-vowel tokens. Perceptual & Motor Skills: Perception 118, 210-224.
  • Guillot, K., Ohde, R., & Hedrick, M. (2013). Perceptual development of nasal consonants in children with normal hearing and in children who use cochlear implants. Journal of Speech, Language, and Hearing Research, 56, 1133-1143.
  • Hedrick, M., Bahng, J., von Hapsburg, D., & Younger, M. (2011). Weighting of cues for fricative place of articulation perception by children wearing cochlear implants. International Journal of Audiology 50, 540-547.
  • Lee, J.-L., Harkrider, A., & Hedrick, M. (2012). Electrophysiological and behavioral measures of phonological processing of auditory nonsense V-CV-VCV stimuli. Neuropsychologica, 50, 666-673.
  • Rishiq, D., Harkrider, A., & Hedrick, M. (2012). Acceptable noise level (ANL) and psychophysical masking. American Journal of Audiology, doi:10.1044/1059-0889 (2012/11-0021).
  • Hedrick, M. (2010). Hearing. In Handbook of Physics for Medicine and Biology, edited by Robert Splinter. London; Taylor & Francis.
  • Hedrick, M., & Madix, S. (2009). Effect of vowel identity and onset asynchrony on concurrent vowel identification. Journal of Speech, Language, and Hearing Research 52, 696-705.
  • Harkrider, A. W., Plyler, P., & Hedrick, M. (2009). Effects of hearing loss and spectral shaping on identification and neural response patterns of stop-consonant stimuli in young adults. Ear & Hearing 30, 31-42.
  • Hedrick, M. S., & Younger, M. S. (2007). Perceptual weighting of stop consonant cues by normal and impaired listeners in reverberation versus noise. Journal of Speech-Language-Hearing Research, 50, 254-269.
  • Harkrider, A. W., Plyler, P., & Hedrick, M. S. (2005). Effects of age and spectral shaping on perception and neural representation of stop consonant stimuli. Clinical Neurophysiology, 116(9), 2153-2164.
  • Harkrider, A. W., & Hedrick, M. S. (2005). Acute effect of nicotine on auditory gating in smokers and non-smokers. Hearing Research, 202, 114-128.
  • Hedrick, M. S., & Nabelek, A. K. (2004). Effect of F2 intensity on identity of /u/ in degraded listening conditions. Journal of Speech, Language, and Hearing Research, 47, 1012-1021.

Courses Taught

  • ASP 542 - Hearing Disorders
  • ASP 303- Introduction to Hearing Science
  • ASP 586- Standards and Practice Issues in Audiology
  • ASP 602- Psychoacoustics
  • ASP 604- Molecular Genetics and Pharmacology of Hearing
  • ASP 605- Speech Perception and Hearing Impairment
Mark Hedrick

Contact Information

Mark Hedrick

Department of Audiology and Speech Pathology
University of Tennessee
559 S. Stadium Hall
Knoxville, TN 37996-0740

Phone: (865) 974-8105