Shift in stimulus range and the exponent of the power function for loudness

Area of Science:

• Psychoacoustics
• Auditory Perception

Background:

• The exponent of the power function describes loudness perception.
• Auditory adaptation and range effects can influence psychophysical function exponents.

Purpose of the Study:

• To investigate how changes in auditory stimulus range affect the exponent of the power function for loudness.
• To determine if prior stimulus range experience influences post-shift loudness perception.

Main Methods:

• Ten groups of ten subjects each were tested across nine conditions involving shifts or no shifts in stimulus range (weak, strong, complete).
• The exponent of the power function for loudness was measured before and after a stimulus range shift over 60 trials each.

Main Results:

• Preshift exponents varied significantly by stimulus range: weak (highest), complete (intermediate), strong (lowest).
• Postshift exponents were highest for the weak series, but not reliably different for complete and strong series.
• Exponents were significantly influenced by the preshift range and effects persisted for up to 60 trials.

Conclusions:

• Loudness perception, quantified by the power function exponent, is significantly influenced by the range of auditory stimuli experienced.
• Prior stimulus range exposure creates persistent adaptation effects on loudness perception, even after the range is altered.