LowFreq

LowFreq is a simple, free sound level meter with a detailed low-frequency spectrum. - CURRENT LEVEL A-weighted sound level in dB(A), averaged over the last second (equivalent continuous level), plus the unweighted level. A-weighting follows the IEC 61672-1 formula. - STATISTICS Average level (LAeq) since you started, the maximum, and elapsed time. Tap reset to start over. - LOW-FREQUENCY SPECTRUM 20–400 Hz at about 1.5 Hz resolution. Tap any peak to read its exact frequency and level, handy for spotting a hum from a transformer, pump or fan. - CALIBRATION Phone microphones differ from one device to another. Compare with a calibrated sound level meter and adjust the offset in 0.1 dB steps. Privacy: sound is analyzed live on your iPhone. Nothing is recorded, saved or uploaded. No account, no ads, no tracking, no in-app purchases. Note: each point of the spectrum covers only about 1.5 Hz, so it reads much lower than the overall level. The app interface is currently in Chinese.