Researcher in UK seeking help on US Sonar Recordings

Mr. David Tompkins, a writer in the UK, is seeking help on "SONAR training records used by the SONAR / radar training schools in the U.K. during WW2. I assume it would've been for the ASDIC systems? I wondered any US SONAR recordings, or something similar to what you have, might've been used by the...read more