I want to measure sound in dB(A) in iPhone.
How can I do it?
Is there any example or tutorial?
If you use AVAudioPlayer, you can use this method
AVAudioPlayer *avPlayer = ...
[avPlayer play...];
[avPlayer averagePowerForChannel:0];
[avPlayer averagePowerForChannel:1];
From Apple's doc
- (float)averagePowerForChannel:(NSUInteger)channelNumber
Description
Returns the average power for a given channel, in decibels, for the sound being played.
来源：https://stackoverflow.com/questions/6183599/how-to-measure-noise-or-sound-and-displays-in-dba-in-iphone