What the study found
Beam integration reduced low-frequency floor-impact sound in cross-laminated-timber (CLT) floors, and the lower event maximum level, called LAFmax, was associated with listeners hearing the sound as quieter.
Why the authors say this matters
The authors say low-frequency impact noise is a major acoustic weakness in CLT construction, and the study suggests that beam integration is an effective structural way to reduce sub-100 Hz impact noise. The findings indicate that LAFmax, used for simulation or rubber-ball tests, provides a perceptually grounded design metric that complements conventional ratings.
What the researchers tested
The researchers combined a validated finite-element model of a two-story CLT test building with a room-acoustic model to create 12 auralized stimuli. These covered three slab thicknesses, with and without mid-span and quarter-span beams, and were excited by jump-type and run-type forces based on literature values.
What worked and what didn't
Beam integration lowered LAFmax by 1.9 dB, 1.3 dB, and 5.9 dB for the 150 mm, 210 mm, and 270 mm slabs, respectively, with a mean reduction of 3.1 dB. Thicker slabs were consistently quieter than thinner ones, and both magnitude-estimation judgments and paired-comparison judgments were strongly associated with LAFmax. The abstract does not report a case where beam integration increased perceived loudness or produced a contrary pattern.
What to keep in mind
The study used 20 normal-hearing adults in a semi-anechoic room, so the results are limited to that listening setup and participant group. The abstract does not describe broader building types, long-term performance, or other limitations beyond the available summary.
Key points
- Beam integration lowered low-frequency impact sound in CLT floor systems.
- LAFmax dropped by 1.9 dB, 1.3 dB, and 5.9 dB for the 150 mm, 210 mm, and 270 mm slabs.
- Listener loudness judgments were strongly correlated with LAFmax.
- The study used a two-story CLT model, room-acoustic simulation, and auralized stimuli.
- The participant test involved 20 normal-hearing adults in a semi-anechoic room.
Disclosure
- Research title:
- Beam integration reduced low-frequency impact sound in CLT floors
- Authors:
- Toshimitsu Asakura, Haruki Mizunuma, Atsuo Hiramitsu
- Institutions:
- Tokyo University of Science, Building Research Institute
- Publication date:
- 2026-02-23
- OpenAlex record:
- View
- Image credit:
- Photo by Possessed Photography on Unsplash · Unsplash License
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