Spectral envelope and context effects in the tritone paradox

Area of Science:

• Psychoacoustics
• Auditory Perception
• Music Cognition

Background:

• The tritone paradox describes the perception of chroma differences in octave-complex tones.
• Previous theories suggested individual pitch-class templates determine perceived pitch direction.
• Spectral envelope shifts have been observed to alter this perception.

Purpose of the Study:

• To investigate the influence of spectral envelope on the perception of the tritone paradox.
• To determine the extent to which listeners rely on spectral envelope versus pitch class.
• To examine contextual influences on tritone perception.

Main Methods:

• Reanalysis of existing data on tritone perception.
• Experimental manipulation of spectral envelope center frequency.
• Presentation of isolated tone pairs and contextual stimuli.
• Testing with Deutsch's tritone test CD.

Main Results:

• A strong tendency exists to perceive the pitch class at the spectral envelope's center frequency as subjectively lowest.
• Listener reliance on spectral envelope varies, with some being fully dependent, others pitch-class dependent, and some showing mixed patterns.
• Perceived direction of tritone pairs is easily influenced by preceding auditory context.
• Strong spectral envelope effects were confirmed even with established tritone tests.

Conclusions:

• Subjective pitch height of octave-complex tones is determined by multiple factors, including spectral envelope and context, not solely pitch class.
• Individual differences significantly affect the weighting of spectral envelope cues in pitch perception.
• The spectral envelope plays a crucial role in resolving pitch ambiguities in the tritone paradox.