Docker Customisation in AI Workbench - /dev/snd mapping

I am using AI Workbench with the DGX Spark, and one application I am doing uses the Microphone and faster-whisper. Using the AI Workbench, the project is run in a container, and access to /dev/snd is restricted. Normally you can pass the device into the container with
”–device” used in the container start commands.
Where can such commands be added to the container configuration? AI Workbench seems to restrict Hardware changes to the number of graphic cards and memory reservation.
Many thanks in advance