Near-Field Sound Localization Based on the Small Profile Monaural Structure

Area of Science:

• Acoustics
• Signal Processing
• Sensor Technology

Background:

• Near-field acoustic waves exhibit complex temporal, spectral, and spatial properties.
• Traditional sound localization methods face challenges in confined or near-field environments.

Purpose of the Study:

• To develop and validate a compact, single-microphone near-field sound localizer.
• To leverage asymmetric structural features for directional sound identification.

Main Methods:

• A physical structure with ten pipes of varying lengths and radial wings was designed.
• A modified Cepstral parameter was used to estimate the fundamental frequency generated by acoustic resonance.
• A dedicated algorithm derived the length and angle of arrival (AoA) from the estimated fundamental frequency.

Main Results:

• The system demonstrated directional localization capabilities using spectral variations induced by the asymmetric structure.
• Extensive acoustic experiments with a 3D-printed model yielded average hit rates of 89% for direct paths and 73% for side paths.
• Localization accuracy increased at closer distances, achieving an overall 78% hit rate up to 15 cm.

Conclusions:

• The proposed single-microphone near-field sound localizer effectively utilizes structural asymmetry for directional sound identification.
• The system shows promise for compact acoustic sensing applications requiring precise near-field localization.
• Further research can explore optimizations for enhanced accuracy and extended range.