Listeners hear tones that are absent from the presented sound

Evidence

There are several phenomena related to tones that are perceived but not present. Perhaps they are the analog of the visual effect just mentioned: side effects of auditory processing. They go under the names of Tartini tones, difference tones, combination tones, beat tones, resultant tones, distortion products, differential tones, summation tones, and no doubt more. Some of these terms are overlapping, and others have not ever received crisp definitions or usage. We will not succeed in defining a zoo of these effects with every one in a different cage. — Eric J. Heller, Why You Hear What You Hear- An…, 2275

Categorization

• DEFINE: Lays out the messy, overlapping vocabulary of subjective tones that the chapter will then unify.