Standardization and Calibration Part 2: Brief Stimuli, Immittance, Amplification, and Vestibular Assessment

I had the great good fortune to be accepted as an Audiology Master's student at the University of Wisconsin–Madison in the mid-1970s. Ray Karlovich and Terry Wiley provided me with an excellent foundation in acoustics and instrumentation. Neither would accept a superficial understanding of the physical sciences from their audiology students—they wanted us to understand the theoretical and computational bases of the relevant physical sciences, so we could apply this understanding to each patient we saw in the clinic. In my Ph.D. program at Wisconsin, I focused on auditory physiology, especially in the area of auditory evoked potentials. My mentors in evoked potentials, Bob Goldstein and Kurt Hecox, taught me a lot about the evoked responses themselves, and yet it was Ray's and Terry's acoustics and instrumentation that helped me figure out how to calibrate the transient stimuli typically used to elicit auditory evoked potentials. One of my early publications described several approaches to calibrating the level of acoustic transients and the spectral analyses of these transients.[1] In the sensory domains, it is not possible to directly measure perception, and so we must use some response (e.g., the push of a button, the raising of the hand, the recording of an auditory brainstem response) as a surrogate measure of the actual percept. This means that if we do not fully and accurately quantify the acoustic (or other sensory) stimulus, then the response is largely meaningless. Now, more than 35 years after taking coursework from Ray and Terry, I still use the knowledge and skills gained in their courses on a very regular basis. I have used this knowledge to calibrate the stimuli I use in my experimental investigations. I have passed along this knowledge in book chapters. I served as the Vice Chair and Chair of American National Standards Institute (ANSI) S3 Bioacoustics, which would not have been even remotely possible without the mentorship and teaching skills of Ray Karlovich and Terry Wiley.

When Catherine Palmer, Editor-in-Chief of Seminars in Hearing, contacted me about editing a volume on calibration and standards, I decided it was time to combine, in two issues, the various aspects of calibration and standardization relevant to the practicing audiologist. I recruited experts in acoustics (and related physical sciences), as well as experts in the standardization process (both international and national standards), so that those students, clinicians, and researchers not so lucky to have mentors like Ray and Terry have a place to go to learn about acoustics and standards. For some articles, I combined experts in International Organization for Standardization/International Electrotechnical Commission standards with experts in ANSI standards. Sometimes I recruited folks with expertise in standardization with folks with scientific expertise in the topic area. In the process, I sometimes put together experts who knew one another, and in other cases individuals who had never before met. After a prolonged gestation period and an occasionally painful labor process, the issues of Seminars in Hearing you have before you were born. Due to my advancing age, future procreation is unlikely.

• Reference

• 1 Burkard R. Sound pressure level measurement and spectral analysis of brief acoustic transients. Electroenceph Clin Neurophysiol 1984; 57: 83-91