A mysterious, low-frequency noise has settled over the small town of Omagh in Northern Ireland, and is keeping people awake. It’s called “The Hum,” and reports of this phenomenon have been popping up ...

Islanders in the Outer Hebrides whose lives are being disrupted by a mysterious humming sound say they believe the source is military operations in the North Atlantic. The persistent low frequency ...

Researchers describe an acoustic meta-surface that uses pingpong balls, with small holes punctured in each, as Helmholtz resonators to create inexpensive but effective low-frequency sound insulation.