Annoying noise-what the automotive industry calls "buzz, squeak, and rattle" (BSR) -- is the leading cause of customer complaints about new cars. Eliminating noise during the design and prototyping phase can pay big dividends, but locating transient, intermittent, ill-defined sounds like BSR or cricket chirps can be exasperatingly difficult.
Designers at Hyundai Motor Group enlisted SM Instruments, a Korean acoustic-engineering firm, to help them quickly locate irritating 200 Hz-to-20 kHz noises in car engines, bodies, instrument panels, seats, doors, any place components can vibrate or rub. The result was the SeeSV-S205, a compact, hand-held "sound camera" -- an array comprising dozens of inexpensive-but-sensitive MEMS microphones (similar to those found in cell phones) in a five-armed spiral around a video camera.
The device (like other acoustic cameras that have preceded it) compares the signals from all of the microphones-the process is called beamforming -- to trace the incoming sound back to its source.