Find files in Terminal by kind - not extension?
To search all files with a distinctive kind use the command:

mdfind 'kMDItemKind="Sound Designer II audio"'


If this is not sufficient you can also use the type code (yyyy below is a place holder only)

mdfind 'kMDItemFSTypeCode="yyyy"'


You should be able get an (unknown) type code of a Sound Designer II audio file by executing mdls "/path/to/Sound Designer II audio file" | grep kMDItemFSTypeCode