Blind-tested listeners with normal hearing produce reliable, measurement-grade subjective ratings

Evidence

My very first simple blind experiments showed that non-auditory factors are powerful biases. Subsequent tests have proved it. We now know that, given the opportunity to judge sound quality alone, humans with normal hearing yield remarkably repeatable subjective ratings on loudspeakers, providing the key to understanding what measurements mean. Experienced listeners, with or without specific training, agree on what sounds “good”. They are so reliable that they are worthy of the title “measurements”. From published statistics on hearing loss, it seems that approximately 75% of the population qualify for this purpose as having sufficiently “normal” hearing: within about 20 dB of audiometric zero over most of the tested frequencies. — Toole, Floyd E, Sound reproduction- the acoustics and…, 51

Categorization

• DEFINE: ‘Normal hearing’ is pinned down operationally: within about 20 dB of audiometric zero over most tested frequencies, covering roughly 75% of the population.
• XREF: Connects to listener-training and loudness-matching research in psychoacoustics and to the reliability of expert panels generally.