-It seems you always outIndex = inIndex (#define NUM_OF_BUFFERS (1u))
-DMA Hardware Request = Level ????
-еnable nrq for DmaDone: CyDmaTdSetConfiguration(.......... TD_INC_SRC_ADR|DMA__TD_TERMOUT_EN);
Add .... TestPin_Write(1); TestPin_Write(0);..... for analyzer - helps to see problems
You can also have a look at this project. However this is USB-PDM bridge, but th elogic could be used with USB - I2S project. You can also have a look at the PSoC4200L family based USB-I2S project examples. CY8CKIT-046 based cod example has an audio project. Plesae have a look at the same.