---

Research topics

I am director of the Biomedical Engineering Bioacoustics Laboratory. The laboratory was founded in 1971 as the research activity of the department of otolaryngology in the medical school. Close ties remain with various programs in the School of Medicine, although the laboratory was transferred in 1995 to the newly formed School of Engineering.

My primary research interest is in animal bioacoustics. The focus of sponsored research is on the bioengineering aspects of animal behavior/physiology including the effects of man-made noise on fish, reptiles, birds and mammals and the evolutionary biology of the sense of hearing.

Human studies have concentrated of the nosology of language and listening disorders. Specific attention was directed to electrophysiological markers of processing disorders and in the case of central auditory disorders, animal models (jaundice or metabolic deficient rats). Over the last decade research emphasis has been on the development of communicative and orienting aids for the deaf, blind and safety workers using audible ultrasound between 20,000 and 100,000 Hertz. Both projects are licensed for commercialization. Safety studies of sonic and airborne ultrasound are under way.
Current activities involve federal funding (U.S. Army Corps of Engineers and U.S. Air Force) as well as corporate partners (Raven Inc., Center for Innovative Technology in Virginia, Sound Techniques System) to develop devices to aid human disease recovery and reduce sea turtle collisions with dredges and birds with aircraft. Stimuli range from sub and sonic sources for turtles to microwaves with birds and ultrasound with humans.

Classes Taught

• ENGB 301 Practicum
• ENGR 491/691 Intellectual Property
• ENGB 635 Modeling

Current Projects

• Non-invasive cerebral spinal fluid pressure device
• High noise speech communication system
• Baby echolocator is a device to allow deaf babies to "see" acoustically facilitating perceptual motor development
• Baby multimodal (bone conduction and vibrotactile) hearing aid using algorithms to track mothers voice
• Tinnitus (phanton sound sensation) management system using very high frequency stimulation with custom actuators (see: www.tinnitus.vcu.edu)

Education

• B.S. Biology, Seton Hall University, South Orange, New Jersey, 1966
• M.S. Audiology Speech/Language Pathology, Seton Hall University, 1968
• Ph.D. Psychoacoustics and Speech Science, Florida State University, Tallahassee, Florida, 1970
• Au.D. Kirksville College of Osteopathic Medicine, ASHS, Mesa, Ariz., 2001

Publications

• Goldstien, B., Shulman, A., Lenhardt, M.L., Richards D.G., Madsen, A., Guinta, R. Long-term Inhibition of Tinnitus by UltraQuiet™ Therapy: Preliminary Report International Tinnitus Journal, in press, 2002.
• Moein-Bartol, S.E., Musick, J.A. and Lenhardt, M.L. Auditory evoked potentials of the loggerhead sea turtle (Caretta caretta) Copeia, August, 1999.
• Lenhardt, M.L., Skellett. R., Wang. P. and Clarke, A.M. Human ultrasonic speech perception Science 253: 82-85, 1991.
• Lenhardt, M.L. Tones in their bones The Sciences July/August, 40-43, 1985.
• Lenhardt, M.L. Childhood central auditory processing disorder with evoked potential verification Archives of Otolaryngology 107: 623-625, 1981.
• Lenhardt, M.L. Vocal cues in maternal recognition of goat kids Applied Animal Ethology 3: 211-219, 1977.
• Lenhardt, M.L. Effects of frequency modulation on auditory evoked responses Audiology 10: 12-18, 1972.