The Scope and Limits of Iconic Prosody: Head Angle Predicts f0 Changes While Object Size Effects Are Absent

Area of Science:

• Linguistics
• Speech Science
• Acoustic Phonetics

Background:

• Previous research linked voice fundamental frequency (f0) to vertical space, but mechanisms remain unclear.
• Iconic prosody, where vocalizations mimic sensory experiences, is a key area of interest.

Purpose of the Study:

• Investigate the relationship between head angle and f0 in iconic prosody.
• Examine the influence of object size on lip opening and formant frequencies.

Main Methods:

• Participants produced speech (
• piff
• paff
• ) while interacting with objects of varying sizes and vertical positions.
• Head angle and f0 were measured to assess their predictive relationship.

Main Results:

• Head angle reliably predicted f0, with increased angle correlating with higher f0.
• Object vertical position also affected f0, but head angle was a stronger predictor.
• Object size did not predict lip opening or formant dispersion, indicating these are not driven by external object properties.

Conclusions:

• Head angle is a primary physiological mechanism modulating f0, supporting its role in iconic prosody.
• Vocal parameters like lip opening and formant dispersion are indexical, reflecting articulatory configurations rather than object size.