Differential sensitivity to pitch distance, particularly in speech

Area of Science:

• Psychoacoustics
• Speech Perception
• Auditory Neuroscience

Background:

• Fundamental frequency (F0) variations shape speech intonation.
• Listener sensitivity to F0 changes is crucial for understanding intonation perception.
• Traditional just noticeable difference (jnd) measures may not fully capture intonation perception.

Purpose of the Study:

• To investigate listener sensitivity to the amount of F0 change in speech.
• To differentiate between pitch contour perception and simple pitch discrimination.
• To compare F0 perception in speech with musical interval perception.

Main Methods:

• Two experiments examined sensitivity to upward and downward F0 changes in speech stimuli.
• Participants (n=74 and n=104) with varying musical ability were categorized.
• Similar experiments were conducted using piano tones to assess musical interval sense.

Main Results:

• Listeners were categorized into nondiscriminators (<4 semitones), final pitch discriminators, and pitch distance discriminators (1.5-2 semitones jnd).
• Results for speech stimuli were similar to those obtained with piano tones.
• Significant differences in F0 perception were observed based on listener categorization.

Conclusions:

• Listener sensitivity to F0 changes varies significantly.
• Only F0 differences exceeding 3 semitones appear relevant in communicative contexts.
• Perception of pitch distance, not just final pitch, is key to understanding speech intonation.