How to set the gain of the pdm module in nrf52832

[?????]

As I don't know much about audio,I have trouble with the gain of the pdm module in nrf52832.Now I have used MP45DT02 as the digital microphone,but I just can't understand the gain about the pdm module in the datasheet.I have tried to change the gain value,but it seem to have no effect on the audio.It also has too much noise.Could you give me some advice?

[Jørn]

The PDM module of the nRF52832 converts the PDM signal to PCM. The gain set in the register should then alter the numerical value for each sample. How do you play the sound? Do you have a figure showing how you have connected your microphone and speaker to the nRF?