Accelerometer based measurement for the mapping of neck surface vibrations during vocalized speech

Area of Science:

• Biomechanics
• Acoustics
• Bioengineering

Background:

• Laryngeal vibrations are being investigated as a communication channel.
• Accurate measurement of these vibrations is crucial for applications like electro-larynx devices for laryngectomees.

Purpose of the Study:

• To map skin surface vibration amplitudes during vocalization.
• To identify suitable locations for laryngeal vibration measurement.
• To explore the information contained within time-varying acceleration signals.

Main Methods:

• Used a low-inertia analog accelerometer (5x5x1.6mm, 80mg) connected to a 12-bit analog-to-digital converter.
• Simultaneously sampled accelerometer output and microphone audio signal.
• Measured vibrations at 45 locations on the neck of two male subjects vocalizing the vowel sound /i/ at 150Hz, 200Hz, and 250Hz.

Main Results:

• Presented a detailed map of skin surface vibration amplitude during vocalization.
• Identified specific locations suitable for laryngeal vibration measurement.
• Revealed rich and complex information in time-varying acceleration data, visualized through novel methods.

Conclusions:

• Established a methodology for measuring and mapping vocalization-induced neck vibrations.
• Highlighted the potential for using these vibration maps to inform the placement of assistive communication devices.
• Demonstrated the complexity and information richness of laryngeal vibration signals.