[Digilent Pmod I2S2 stereo]

I am using pmod i2s2 and it is working fine with transmission data ,

Now I need to use it as a RX from an external mic I use this converter to use my normal headphone for both mic and speaker, 

and Iam trying to loop back the data I recorded , I use MCLK = 25 MHz , LRCLK = 48.8K hz , SCK = 3.128 Mhz   (and these clocks are configurable)

but I donot hear anything of the recording data.
should I use an amplifier ?

or should I configure anything else other than the clocks

Pmod is operating as slave