Ear Impression History
An ear impression has most often been used to fabricate an earmold (earpiece) that fits into portions of the outer ear to direct amplified sound toward the tympanic membrane (Figure 1). Essentially, an ear impression is made by placing a viscous, thixotropic impression material into the concha and part of the ear canal. When it…
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Hearing Testing History: Western Electric 2-A Audiometer
Western Electric 2-A Audiometer Most hearing care professionals have heard or read that one of the early audiometers for the measurement of hearing sensitivity was the Western Electric 2-A audiometer. Few have any idea what it looked like or what it did. This post is pleased to bring to readers some of the best detailed…
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