This is the sample code developed during my Msc, where I created a UEFI application capable of processing sound streams at UEFI environment.
https://github.com/RafaelRMachado/Msc_UefiHda_PreOs_Accessibility
see-also:
https://firmwaresecurity.com/2018/11/28/audiopkg_-intel_hda_uefi_driver_wip/