The frequency scale of speech intonation

Area of Science:

• Phonetics
• Psychoacoustics
• Auditory Perception

Background:

• Intonation research traditionally uses linear or logarithmic frequency scales for pitch movements.
• The psychoacoustic scale, reflecting auditory system frequency selectivity, offers an alternative perceptual framework.
• Investigating pitch perception across different registers is crucial for understanding intonation.

Purpose of the Study:

• To determine if speech intonation pitch movements are perceived on linear, logarithmic, or psychoacoustic scales.
• To compare pitch perception across different speech registers using matched prominence levels.

Main Methods:

• An experiment was conducted involving subjects matching pitch excursion sizes in resynthesized speech stimuli.
• Stimuli were presented in different pitch registers (low and high) and on linear, logarithmic, or psychoacoustic scales.
• Participants adjusted comparison stimuli to achieve equal prominence with fixed test stimuli.

Main Results:

• Subjects consistently matched pitch excursion sizes across different registers on the psychoacoustic scale.
• This indicates that perceived prominence in speech intonation is governed by the psychoacoustic scale.

Conclusions:

• Perception of prominence-lending pitch movements in speech is best described by the psychoacoustic scale.
• This finding challenges traditional linear and logarithmic scale models in intonation research.
• The results highlight the importance of psychoacoustic principles in understanding speech prosody.