T41P with YHS32 Headset Microphone Volume Issue

Hi All

I am using a few T41P Handsets with YHS32 Headsets and finding that the Microphone Volume is very low. The web interface appears to have no option for increasing the Mic Volume or Gain and I was hoping that someone may have a solution for this?

I am using Firmware Version 36.73.0.50 the handsets also.

Thank you very much in advance
Dan