Batteries for Early Transistor Hearing Aids

The transition from vacuum tube to transistor hearing aids occurred in the mid 1950s.  The transistor allowed for a single power supply, and voltage as low as 1.4. Being able to operate on 1.4 volts reduced tremendously the power requirements, both in size and required voltage from that required for vacuum tube hearing aids.  Essentially…

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Intelligibility vs. Bandwidth

A Case for Mid-frequency Amplification (Continued) Should mid-frequencies be given more than a cursory consideration when it comes to fitting hearing aids? Last week’s post reviewed some acoustic characteristics of speech and their significance in speech perception. These included long-known information related to speech spectra; the relationship between speech power, frequency, and intelligibility; critical bands;…

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