Android OpenSL ES, how to choose speaker

Does anyone know how to play the sound through the speaker that we normally use during the phone conversation (not the loud speaker, but the ear speaker)? I have developed the app similar to Skype and my only problem is that when the sound is played through the loud speakers, mic picks it up and there is a lot of nose generated... In my code this is the line that I figured controls which speaker is used...

SLDataFormat_PCM format_pcm = {SL_DATAFORMAT_PCM, 1, SL_SAMPLINGRATE_8,
                                   SL_PCMSAMPLEFORMAT_FIXED_16, SL_PCMSAMPLEFORMAT_FIXED_16,
                                   SL_SPEAKER_FRONT_CENTER, SL_BYTEORDER_LITTLEENDIAN};

There are other options instead of SL_SPEAKER_FRONT_CENTER namely:

#define SL_SPEAKER_FRONT_LEFT           ((SLuint32) 0x00000001)
#define SL_SPEAKER_FRONT_RIGHT          ((SLuint32) 0x00000002)
#define SL_SPEAKER_LOW_FREQUENCY        ((SLuint32) 0x00000008)
#define SL_SPEAKER_BACK_LEFT            ((SLuint32) 0x00000010)
#define SL_SPEAKER_BACK_RIGHT           ((SLuint32) 0x00000020)
#define SL_SPEAKER_FRONT_LEFT_OF_CENTER ((SLuint32) 0x00000040)
#define SL_SPEAKER_FRONT_RIGHT_OF_CENTER    ((SLuint32) 0x00000080)
#define SL_SPEAKER_BACK_CENTER          ((SLuint32) 0x00000100)
#define SL_SPEAKER_SIDE_LEFT            ((SLuint32) 0x00000200)
#define SL_SPEAKER_SIDE_RIGHT           ((SLuint32) 0x00000400)
#define SL_SPEAKER_TOP_CENTER           ((SLuint32) 0x00000800)
#define SL_SPEAKER_TOP_FRONT_LEFT       ((SLuint32) 0x00001000)
#define SL_SPEAKER_TOP_FRONT_CENTER     ((SLuint32) 0x00002000)
#define SL_SPEAKER_TOP_FRONT_RIGHT      ((SLuint32) 0x00004000)
#define SL_SPEAKER_TOP_BACK_LEFT            ((SLuint32) 0x00008000)
#define SL_SPEAKER_TOP_BACK_CENTER      ((SLuint32) 0x00010000)
#define SL_SPEAKER_TOP_BACK_RIGHT       ((SLuint32) 0x00020000)

I have tried all of them and none work. Thanks Alex.