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Sound Absorption

Ilene Busch-Vishniac has established a career focused on the goal of mastering sound-both clarifying sounds that people want to hear and quelling sounds that they don't.

Busch-Vishniac said that her parents had hoped she would become a lawyer. Instead, she entered college as a music major, studying piano at the Eastman School of Music and taking academic classes at the University of Rochester. After one semester she realized that she didn't possess the talent or the drive she thought she needed to become a successful performer. But she had taken a freshman seminar called physics of music that got her interested in acoustics. So in her second semester, she switched her major to physics and mathematics.

After completing her undergraduate studies at the University of Rochester, Busch-Vishniac headed to MIT where she continued to study acoustics and earned master's (1978) and doctoral (1981) degrees in mechanical engineering. As a graduate student, she developed computer tools for studying problem noise in the suburbs and investigated how to produce quieter impact line computer printers.

Soon after, Busch-Vishniac worked as a post-doc and researcher at Bell Labs. There she developed devices for microphones and earphones and improved conference calling systems to eliminate echo that some speakers can have. She has several patents on her technology.

In 1982, Busch-Vishniac joined the faculty at the University of Texas at Austin and was later named Temple Professor of Mechanical Engineering. At Austin, she started to work on ways to reduce the level of noise that comes from transportation. She has also investigated methods of building more effective, less expensive highway sound barriers. The solution, she said, appears to lie in the geometric design of the barrier, not in its composition.

Later, in 1998, Busch-Vishniac went to work as Dean of Engineering at Johns Hopkins University's Whiting School of Engineering in Baltimore where she continues to work today. There Busch-Vishniac continues to focus her research interests on the highway noise barriers that are built to spare local residents the disturbance of freeway traffic. Existing barriers have had mixed success because it is nearly impossible to gage a design's sound-absorbing properties until it's actually been installed alongside a roadway--at a cost of 1 to 2 million dollars a mile. Busch-Vishniac and her collaborators believe they've found a solution to the problem in randomly varying the height of the barriers, which in effect breaks up the sound waves.

Just twenty years after she first launched her career, Busch-Vishniac is counted among the world's leading authorities on electromechanical sensors and actuators. (These devices convert mechanical energy--such as sound waves--to electrical signals, and vice versa, much as it happens at either end of a telephone line.) She has collected a number of honors and awards for her work. In 1997, she won the Society of Women Engineers' Achievement Award. In 1995 she was named a National Science Foundation Presidential Young Investigator. She was recipient in 1987 of The Acoustical Society of America's Lindsay Award, and in 1995, she was recipient of the American Society of Engineering Education's Curtis McGraw Research Award.