Suitability of a consumer digital recorder for use in acoustical measurements

MIYARA, FEDERICO; ACCOLTI, ERNESTO; PASCH, VIVIAN; CABANELLAS, SUSANA; YANITELLI, MARTA; MIECHI, PABLO; MARENGO RODRIGUEZ, FERNANDO; MIGNINI, EZEQUIEL

Lisboa, Portugal

Congreso; 39th International Congress and Exposition on Noise Control Engineering (INTER-NOISE); 2010

nternational Institute of Noise Control Engineering (I-INCE), Portuguese Acoustical Society (SPA) and the Spanish Acoustical Society (SEA)

Signal acquisition in acoustical metrology is an increasing need in research and fieldwork. Many specialists think that new indicators should be introduced to describe effects of noise arising from features such as spectrum, semantic content and psychoacoustic properties of noise, all of which require a knowledge of the time history of signal. While there are several instrumentation grade recorders (some of which are optional upgrades for recent models of sound meters), they are usually expensive. The possibility of using a relatively inexpensive digital recorder (Zoom H4) in combination with the calibrated output signal of a precision sound level meter is explored. The major concern arises from the high frequency effects of the antialiasing filter of the analog to digital converter. Three units of the same model of digital recorder were extensively tested as regards frequency response, noise, distortion and transient response at two sampling rates, 44100 Hz and 96000 Hz. Electrical signals applied at the recorder input were monitored with a volt meter and an oscilloscope, while the recorded digital signal was transferred to a computer for software analysis. Tests reveal that the recorder is suitable for use as part of a measurement setup.