Hi @ptrblck,
How should I pass the channels_first  keyword to the DownmixMono  function?
I get the following error.
torchaudio.transforms.DownmixMono()(sound[0],channels_first = True)
__init__() got an unexpected keyword argument 'channels_first'
However this works but I get wrong dimensions as mentioned by OP:
torchaudio.transforms.DownmixMono()(sound[0])