Turning off AGC on the iPad

There is little consensus on whether the iOS interface Apple provides to shut off automatic gain control is actually implemented. Does anyone know definitively if it is possi开发者_如何学运维ble to shut off AGC when recording audio on the iPad and, if the answer is yes, how?

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if you are using iOS< 5...the answer is NO.

if you are using iOS>=5 on an iPad2...the answer is still NO. Not

if you are using iOS>=5 on iPhone 3GS, iPod(4th gen), iPad1 (1st gen) the answer seems to be YES.

ACG is turned off when the AudioSessionMode is changed to kAudioSessionMode_Measurement. Check the Audio Session Services Reference.

input gain can be controlled by:

1) Set your audioSession's mode to kAudioSessionMode_Measurement.

2) Be sure that the device you are using has input gain available by using the kAudioSessionProperty_InputGainAvailable property.

3) Set the property kAudioSessionProperty_InputGainScalar to your desired gain level (between 0 and 1.0)

*haven't gotten my hands on the newest iPad yet, so cant confirm.