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Urban Acoustics and Infrasonic Detection of Crowd Noise

Description: 

The efficacy of a 10 meter, six-node hexagonal infrasonic array for detecting crowd-sourced infrasound signals from a football stadium was demonstrated using directional analysis. Data were collected over two three-hour periods: during a football game and a non-event day for comparison. Beamforming techniques analyzed angle of arrival, power, and speed. Results show directional clustering toward the stadium on game days in mid-frequency ranges (4–16 Hz). Similar clustering on non-event days prompted a Watson-Williams test, with a p-value of 0.009, suggesting a significant statistical difference. Rose diagrams and mean direction plots demonstrate tighter clustering toward the stadium direction on game days compared to broader distributions on non-event days. Signal power analysis revealed mid-frequency ranges on event days had elevated stadium-aligned power ratios (e.g., 8–12 Hz ratio of 0.225 versus 0.142 on non-event days), supporting the hypothesis of crowd-induced signals. Low (0–4 Hz) and high (16–20 Hz) frequency ranges showed consistent directional behavior across both days, suggesting influence from ambient noise sources. These findings underscore the array’s ability to detect anthropogenic infrasound amidst urban noise, illustrating potential for geophysical applications in event monitoring and crowd dynamics analysis. We surmise that multiple array stations distributed spatially would improve detection over single station deployment.

Session: Data-driven and Computational Characterization of Non-earthquake Seismoacoustic Sources [Poster]

Type: Poster

Date: 4/16/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Jessica

Student Presenter: Yes

Invited Presentation: 

Poster Number: 81

Authors