I have a USB cassette device that I used to transfer some tapes to my computer. One of them is an old answering machine tape and it runs at a much slower tape speed. So when I play back the recording in Audacity it goes very fast and my voice sounds very high pitched. Is there a way to slow down the playback in Audacity so that it sounds normal?
We can make it sound better, not normal. Tape players change a number of settings to cancel mechanical and electrical tape errors. They go all wonky if you play the tape off-speed.
Effect > Change Speed.
http://manual.audacityteam.org/man/change_speed.html
Natural tape speeds tend to be multiples of 15 inches per second, so 7-1/2, 3-3/4, etc. are all possibilities. 1/2, 1/4, etc.
If you had a weird answering machine, then it’s trial and error.
Koz
The Audacity recording of the tape should be exactly as the tape sounds on playback.
There seems to be problems with Audacity running on Windows10 which causes recordings to have a pitch-shift.
( If you upgraded to Windows 10 maybe you need to update the audio driver to new one compatible with W10 ).
Windows own-brand recorder is worth a try : you can transfer any recording made with it into Audacity for editing.
I got it to work. I used Change Speed… under the Effect menu. First I selected the entire recording, selected Effect → Change Speed… and then I entered a value. I had to enter a negative value because every time I entered a positive value it got faster. LOL. Problem solved.