Project Background
A public higher education institution’s multi-purpose lecture auditorium hosts large-group courses, academic seminars and student assembly events. The large-volume space with solid concrete walls suffers severe mid-low frequency reverberation. Bass resonance renders lecturer speech muddy and indistinct, while students seated in rear seating zones struggle to capture clear audio. Standard porous acoustic materials fail to target the dominant 250Hz–1000Hz low-frequency noise typical of large educational venues.
Solution
Combined grooved and perforated wooden resonant panels were installed on side walls and rear wall surfaces. Designed following the Helmholtz resonance principle, precision engineered hole and groove structures specifically absorb persistent mid-low frequency standing wave noise. Matched rear air cavities and mineral wool backing raise the overall NRC to 0.90, realizing balanced full-band sound absorption. Light neutral wood veneer finishes match the restrained, formal aesthetic standard of campus education architecture.
Final Outcome
Post-renovation acoustic testing verified reverberation time adjusted within the ideal range for academic speech transmission. Overall speech intelligibility increased by 40%, with consistent sound pressure levels across front and rear seating sections. Lecturers no longer need to raise vocal volume to cover full venue capacity, reducing long-term vocal strain for teaching faculty.
