Does fundamental-frequency discrimination measure virtual pitch discrimination?

Area of Science:

• Psychoacoustics
• Auditory Perception
• Pitch Perception

Background:

• Difference limens for complex tones (DLCs) measure fundamental frequency (F0) discrimination.
• DLCs are often used as an indirect measure of subjective pitch strength.
• Discrimination may rely on cues other than F0, like component frequencies or timbre.

Purpose of the Study:

• To investigate whether DLCs primarily reflect F0 pitch discrimination or other auditory cues.
• To compare DLCs for harmonic and inharmonic complex tones.
• To determine the influence of frequency shifting on pitch perception and DLCs.

Main Methods:

• DLCs were measured for harmonic and inharmonic complex tones.
• Inharmonic tones were created by frequency-shifting harmonics by 6.25%, 12.5%, or 25% of F0.
• Conditions included randomized/fixed lowest harmonic number and feedback presence/absence.

Main Results:

• Inharmonic complex tones yielded larger DLCs compared to harmonic tones.
• Pitch matches were more scattered for inharmonic tones, indicating less consistent pitch perception.
• Results suggest that DLCs are sensitive to the consistency of pitch perception.

Conclusions:

• The findings support the hypothesis that DLCs reflect F0 pitch discrimination.
• Inharmonic tones, producing weaker pitch, led to larger DLCs, consistent with pitch ambiguity.
• DLCs are a valid measure for assessing F0 discrimination, particularly when pitch is clearly perceived.