Commercial telephone bandwidth standards derive from interwar human listening tests

Evidence

Starting from the 1920s, Harvey Fletcher and the Bell Laboratories research group (Fletcher, 1995) made fundamental studies that laid the groundwork for engineering psychophysics (psychoacoustics) as a systematic experimental science by making quantitative formulations for articulation and intelligibility of speech. Subjects in listening tests were used as ‘meters’ to ‘measure’ desired factors in speech transmission. This was the basis, for example, for setting the standard of the telephone bandwidth that is still in use today. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2318

Categorization

• XREF: Connects to the reader’s concern with practical applications of acoustic communication — this is the canonical origin of psychoacoustics as an engineering field.
• SEED: A piece on how the telephone bandwidth we still use today was set by 1920s-30s test subjects, a legacy infrastructure standard encoded in hardware for a century.