Microphones and loudspeakers are reversible transducers of pressure and electricity

Evidence

The job of a microphone is to turn acoustic pressure variations into electrical signals. This is just the reverse of the task of a loudspeaker, which turns electrical signals into sound. Indeed, loudspeakers can function in reverse as microphones; and microphones can make sound. (Otoacoustic emissions [see chapter 25] are sounds that come out out of our ears—our “microphone” makes sound!) — Eric J. Heller, Why You Hear What You Hear- An…, 467

Categorization

• DEFINE: Defines the transduction relationship between acoustic pressure and electrical signals and its reversibility.
• XREF: Connects to the ear’s own otoacoustic emissions, which the reading purpose on why we hear what we hear will want to revisit in chapter 25.