Generally, sound tracks on sites linked to eBay auction pages are a distraction . . . a very bad idea. But in those cases where sounds or music are integral to the product offered, they make a great deal of sense. Think -- antique grandfather clocks, toy train locomotives, maritime products, real estate, or rare LP's. It is waykool, for example, to post a soundbyte of the clock striking midnight, the train whistle, marine sound effects, or a 20-second soundbyte from an LP track. It works for me . . .
But remember: eBay permits only certain limited links to your auction page -- including audio or video --which further describe your product. One thing you CANNOT do is sell from your link page. This eBay page details the policy: ( http://pages.ebay.com/help/policies/listing-links.html ).
The way to embed sound into your link page is --
Copy this code into your page to create a sound console:
<embed console="player" src="(insert here your own uploaded music or sound file URL; between the quote marks, no spaces)" controls="ControlPanel"
align="top" border="1" width="300" height="30" volume="30" autostart="true" loop="true">
If copied exactly -- using your own URL -- this will yield a console on your page. The Control Panel allows your viewer to start, pause, or stop the sound and control its volume. I set my Volume arbitrarily at "30". Trial and error will determine your best setting. Use the Autostart feature with care . . . most viewers resent being blasted unexpectedly with loud sound or music. To turn it off, substitute "false" for "true". Loop allows the music or sound to run continually. To cut it off after one play, substitute "false".
I recommend the mp3 file format for music or sound. It is highly compressed (fast upload), high fidelity, and almost universal in scope. My "About Me" page: http://members.ebay.com/ws/eBayISAPI.dll?ViewUserPage&userid=rufusduff contains a sample music console plus links to my home page and its SITEMAP. The latter lists many examples of embedded soundbytes, including some great jazz!
Good Luck and Enjoy!