$19.99 from Faber Acoustical
SoundMeter turns your iPhone or iPod touch into a handheld sound level meter (SLM). The iPhone’s built-in and headset microphones are suitable for basic sound level measurements, but high precision external microphones may also be used.
NOTE: SoundMeter 1.5 is now compatible with the all versions of the iPod touch. To use SoundMeter with the iPod touch, an external microphone is required. On the original iPod touch, an accessory must be attached to the dock connector, which either offers its own microphone or line input. The newer iPod touch also enables input through the headset connector. The default headset microphone sensitivity is set for a standard iPhone headset microphone or the new Apple headphones with remote and mic.
Due to sample rate limitations and frequency response degradation, SoundMeter is not recommended for use with the built-in microphone of first-generation iPhones. SoundMeter will still work with the original iPhone, but when working with the built-in microphone, frequency weighting will be disabled, and the measurement accuracy may be significantly impaired. Using SoundMeter with the iPhone’s included headset microphone, or with the built-in microphone of the iPhone 3G, is recommended.
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 a few dB when using the default microphone sensitivity.
NOTE: SoundMeter has not been shown to meet ANSI or IEC standards for sound level meters.
– 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.
– 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.
– SoundMeter also offers data sharing via photo, email, and Twitter.
– 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. (These limits are due to iPhone hardware, not the SoundMeter software.) Results may vary between iPhones and headset microphones.