I am looking at the SpeakHere example and added the following:

// Overriding the output audio route
UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker; 
AudioSessionSetProperty(kAudioSessionProperty_OverrideAudioRoute, sizeof (audioRouteOverride), &audioRouteOverride);
assert(status == noErr);

// Changing the default output route. The new output route remains in effect unless you change the audio session category. This option is available starting in iPhone OS 3.1.
UInt32 doChangeDefaultRoute = 1;
status = AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryDefaultToSpeaker, sizeof(doChangeDefaultRoute), &doChangeDefaultRoute);
assert(status == noErr);

// Enable Bluetooth. See audioRouteOverride & doChangeDefaultRoute above
// http://developer.apple.com/iphone/library/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/Cookbook/Cookbook.html#//apple_ref/doc/uid/TP40007875-CH6-SW2   
UInt32 allowBluetoothInput = 1;
status = AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryEnableBluetoothInput, sizeof(allowBluetoothInput), &allowBluetoothInput);
assert(status == noErr);

Also,

void AQRecorder::handleInputBufferCallback(void  *aqData,   ...
...

    if (inNumPackets > 0) {
        NSLog(@"Number of samples = %d", inBuffer->mAudioDataByteSize/2); // print out the number of sample

        status = AudioFileWritePackets(aqr->mAudioFile,               
                                            FALSE,
                                            inBuffer->mAudioDataByteSize,
                                            inPacketDesc,
                                            aqr->mCurrentPacket,
                                            &inNumPackets,
                                            inBuffer->mAudioData);
        assert(status == noErr);

        aqr->mCurrentPacket += inNumPackets;
    }

...

Notice the "NSLog(@"Number of samples = %d", inBuffer->mAudioDataByteSize/2); // print out the number of sample" statement above.

I am using iPhone SDK 3.1.3.

I got the following results

1. The number of samples is around 44,100 on Simulator
2. The number of samples is around 22,000 on iPhone
3. The number of samples is around 4,000 on iPhone using Jawbone Bluetooth

I am new on this. Why did itproduce different number of samples?

Thanks in advance for your help.