something I can download to listen to tones and change the frequencies
Thanks

 

Hello,

On this page there are several tone generators:
http://www.educypedia.be/electronics/easoftgenerator.htm

Greetings,
Bertus

 

I think he wants software for a PC.

 

Try Google and pc sound card generator. Lot of hits. I guess you can use one of the links

 

Hello,

The page I provided contains a lot of links to audio generator software.

Greetings,
Bertus