Visual-Spatial Influences on Vocal Intensity: Effects of Speaker-to-Listener Distance and Room Size in Immersive...

Area of Science:

• Speech and Hearing Sciences
• Human-Computer Interaction
• Acoustics

Background:

• Understanding vocal regulation is crucial for effective communication.
• The influence of visual cues, such as listener distance and room acoustics, on voice production is not fully understood.
• Immersive virtual reality (IVR) offers a novel approach to study these factors in controlled, ecologically valid environments.

Purpose of the Study:

• To investigate the effects of speaker-to-listener distance and room size on voice perception and production.
• To determine the primary driver of vocal intensity modulation: listener distance or room size.
• To explore the interaction between room size and listener distance in influencing vocal output.

Main Methods:

• Fifteen vocally healthy participants completed speaking tasks in nine immersive virtual reality (IVR) conditions.
• Conditions systematically varied room size and speaker-to-listener distance.
• Sound pressure level (SPL) was measured for sustained vowels, standardized phrases, and spontaneous speech, with auditory feedback held constant.

Main Results:

• Sound pressure level (SPL) significantly increased with greater speaker-to-listener distances.
• Room size also significantly affected SPL.
• A significant interaction between room size and listener distance indicated that listener distance effects varied with room size, with distance being the primary driver.

Conclusions:

• Visual input, particularly speaker-to-listener distance, is a primary factor in vocal intensity regulation.
• Room size acts as a modulating variable influencing the impact of listener distance.
• Findings support the use of IVR in voice training and therapy to improve functional voice use in realistic contexts.