Stucture-borne noise from a pool
Felicia M. Doggett · The Journal of the Acoustical Society of America · 2019
A problem arose at a recently completed high-rise condominium building in Philadelphia. Tenants on many levels above a pool located on the second level of the building stressed that they could hear low-frequency sound when an early-morning swimmer was doing laps. Looking through literature, we found nothing to attest to the phenomenon that presented itself. To investigate, we used a 15 lb rubber medicine ball to simulate the cavitation caused by the swimmer, which also provided a repeatable source. Cavitation in the water created by the arm strokes of the swimmer was exciting the pool shell and transmitting through the structure ultimately converting to audible sound via the lightweight partitions in the living units. Our measurement system included time synchronized triaxial accelerometers to determine the transmission paths through the building, which identified two significant peaks at 35 Hz and 62 Hz. This case study details this unique problem, the identification of structural transmission, and the successful outcome after our recommendations were implemented.