7.1 Measuring and Scaling Methods in Psycho-Acoustics

As has already been discussed, psycho-physics examines the relationships between particular physical phenomena and the perceptive events associated with them. Psycho-acoustics is a branch of psycho-physics that investigates the relationships between auditory events and sound. Wundt and Fechner are the acknowledged founders of classical psycho-physics ^[68]. Their aim was to mathematically describe the character, size and intensity of phenomena that have been perceived ^[29]. Apart from the classical observation and assessment methods, their means of detecting the absolute threshold, the differential threshold and points of subjective equality have become standard methods:

Detecting the absolute threshold (L):

Exemplary questions: What maximum value can the sound pressure of a sinusoidal sound x have for the listener not to be able to perceive the auditory event? Or: What minimum value can the sound pressure of a sinusoidal sound x have for the listener to just perceive the auditory event?

Detecting the differential threshold (JND = Just Noticeable Difference):

Exemplary questions: If a tone x is given, what value must the sound pressure of a comparable tone y have for the listener to perceive a difference? Or: What value must the sound pressure of a comparable tone y have for the listener not to perceive any difference?

Detecting equivalents (PSE=Point of Subjective Equality):

Exemplary question: Given a tonal sound x with a particular relational frequency (e.g. 1kHz) and a defined sound pressure level, what value must the sound pressure of a comparable tone y of...