Due to popular demand, SoundMeter has arrived to turn your iPhone into a handheld sound level meter (SLM). The iPhone’s built-in and headset microphones exhibit a remarkably flat frequency response, making them suitable for basic sound level measurements. However, due to sample rate limitations and frequency response degradation, SoundMeter is not recommended for use with the built-in microphone of first-generation iPhones.

Even though default sensitivity values are included for the iPhone’s built-in and headset microphones, for best results, SoundMeter should be calibrated before use. Sound levels may be off by 6 dB or more when using the default microphone sensitivity.

Note: SoundMeter has not been shown to meet ANSI or IEC standards for sound level meters.

Valuable Links:
  • Measure time-weighted and equivalent sound levels.
  • Employ Flat, A, or C frequency weighting.
  • Time-weighted measurement options include Fast, Slow, and Impulse weightings.
  • Keep track of peak and maximum sound levels.
  • Produce white noise, pink noise, or single tones.
  • Send sound level data in an email, or post it to your Twitter account.
  • Take a photo with your iPhone and overlay sound level information on top of it. The photo can then be saved to your device's photo library.
  • Save high-resolution sound level display images to the iPhone's Camera Roll photo album. Descriptive text may be added to the image before it is saved.
  • Calibration controls enable automatic calibration, relative to a calibrated sound level meter, or manual entry of the microphone sensitivity.
  • SoundMeter supports rotating the iPhone upside down, so the built-in microphone sits on top of the device when measuring sound levels.
  • With the iPhone’s built-in microphone, SoundMeter can measure peak sound levels of up to approximately 105 dB. With the iPhone’s included headset microphone, SoundMeter can measure peak sound levels of up to approximately 100 dB.
  • Disable the screen auto-lock on your iPhone or iPod touch device.