Solved by ptrblck in post #2 
              
              
                This view operations looks wrong: 
x = x.view(1, 64000)

since you are flattening the tensor such that it’ll have a batch size of 1. 
To keep the batch size equal, use x = x.view(x.size(0), -1) instead. 
In case you would still run into the batchnorm issue, check if the last batch returned by the Da…