With frequency range of 0.13 Hz to 20 kHz, ±2 dB, ½ in. Model 378A07 meets IEC 61094-4 standard for test and measurement microphones. This covers infrasound which is below normal hearing range for adults. A2LA and ILAC accredited, free-field polarized microphone performs measurements commonly required for wind turbines, sonic booms, diesel engines, and specialized loudspeaker systems.