Sound Meter Pro - Decibel & Hz

Sound Meter Pro measures noise in decibels (dB) with your phone's microphone. The sound level meter, statistics and records are free, and a spectrum analyzer and tone generator are in the same app. ■ SOUND LEVEL METER A-, C- and Z-weighting with Fast (0.125 s) or Slow (1 s) response, switched with one tap. A-weighting follows human hearing and is the dB(A) used by most noise rules. All three are calculated at once, so switching never interrupts a measurement. Min, average (Leq), max, peak and elapsed time are always on screen. ■ BUILT FOR ACCURATE READINGS Many meter apps stop at 80–90 dB because of automatic gain control. This app uses unprocessed audio when the phone supports it, or the voice-recognition input without auto gain, with noise suppression turned off. When the microphone nears or reaches its upper limit, the meter tells you instead of silently showing a wrong value. ■ CALIBRATION Phone microphones differ by several dB. Place a calibrated meter next to the phone and use "Match a reading", or adjust in 0.1 dB steps. You only do it once. ■ STATISTICS L10 (loud moments), L50 (median) and L90 (background), the 8-hour equivalent (LEX,8h) and a safe listening time based on NIOSH. ■ GRAPH AND LOUDNESS GUIDE The last 30 s to 5 minutes as a graph, with your threshold as a dashed line. The level is compared with everyday sounds ("like a quiet office"), and the most prominent pitch is shown as a frequency and note. ■ TIMES ABOVE THE THRESHOLD Set a threshold (e.g. 45 dB at night) and the time, duration and maximum of each exceedance are listed and saved. ■ RECORDS Save and name measurements, filter them and open the full graph and statistics. Share a text summary with date, duration, average, max and L10/L90. ■ LONG RECORDINGS WITH THE SCREEN OFF (Premium) Record night-time or neighbourhood noise for hours. The level shows in the notification and progress is saved every 5 minutes. ■ ALERTS AND AUDIO CLIPS (Premium) Vibration and a notification above the threshold, plus an audio clip of each moment, stored only on this phone. ■ CSV AND PDF REPORT (Premium) Every second as CSV, or a PDF report with summary, statistics, graph and every exceedance, ready to print or attach to a complaint. ■ SPECTRUM ANALYZER (Premium) Real-time FFT up to 16,384 points with averaging, peak hold and touch cursor. Spectrum, 1/3 octave, octave and spectrogram views. Peak frequency with musical note and cents. Freeze the view or share it as an image. ■ TONE GENERATOR (Premium) 1 Hz to 22 kHz by typing, 1 Hz and 10 Hz steps, semitones or octaves. Sine, square, triangle and sawtooth; white, pink and brown noise; sweeps; left/right channels and binaural beats; timer, favourites and common tones such as 440 Hz and a 17.4 kHz hearing check. Keeps playing in the background. ■ SPEAKER WATER EJECT (free) After the phone gets wet, a 165 Hz tone plays for 30 seconds to vibrate water out of the speaker grille. ■ MORE Floating meter over other apps and dB in the status bar (Premium), Quick Settings tile, light and dark themes, colour themes (Premium), and a microphone check. ■ FREE AND PREMIUM The sound meter, calibration, statistics, threshold log, records, summary sharing and water eject are free, forever. Premium unlocks the spectrum analyzer, tone generator, long recordings, alerts and clips, CSV and PDF, floating meter and colour themes. It is a one-time in-app purchase, not a subscription, and can be restored with the same Google account. ■ PRIVACY Sound is analysed on the phone and never sent anywhere. Audio is recorded only if you turn on clips. The "display over other apps" permission is used only for the floating meter. No account needed. In 40 languages. ■ PLEASE NOTE A phone is not a certified sound level meter; readings are a reference. Phone microphones are less sensitive below about 50 Hz and above about 16 kHz. Keep tones quiet with earphones.