Speaker's Scale of Vocal Effort
Harvey Lane, A. Charles Catania, S. S. Stevens · The Journal of the Acoustical Society of America · 1960
When a speaker judges the subjective magnitude of his own vocal effort, a power function describes the relation between perceived magnitude and the actual sound pressure produced. Speakers were asked to give numerical estimates of the apparent strength of their own vocal productions, or, conversely, to produce vocal levels in response to numerical criteria stated by the experimenter. The combined evidence from both procedures indicates that the speaker's impression of his own vocal level grows approximately as the 1.1 power of the sound pressure he produces. The power laws governing vocal effort (exponent 1.1) and loudness (exponent 0.6) call be used to predict successfully the outcome of cross-modality comparisons in which subjects try to match their vocal level to criterion sounds of various intensities presented either by loudspeaker or by earphone. The slope of the matching function relating the criterion SPL to the vocal SPL is given by the ratio of the two exponents. What this means is that speakers do not judge their vocal level by listening to themselves, for the sound pressure they produce when they try to match a criterion sound does not grow as fast as the sound pressure of the criterion sound.