If your penis made a sound every time you got an erection,
what would you want that sound to be?  

Opportunity knocking.

But if there just had to be a sound, maybe this one...

Batter Up!!

...The Ride of the Valkyries!!!....

Ask for "permission to come aboard?"

would make a creaking sound like an old door as it achieved full tumescence, and like an old door, once fully "open", it would be stuck that way for at least 45 minutes before you could start to "close" it again.

Nothing like the smell of napalm, er . . . . I mean . . . . pussy in the morning.  

That Hollywood sound of a creaky door opening in a haunted house.

here I cum, ready or not!!!!!

sound

The discomfort of waking up face down with my morning wood, my dick would make a Wilhelm Scream.

Ashley,
If we told you what the tumescence sounds like would you equate that to a medium of exchange?

Anything is possible. Wink.

Followed by Beethoven's "Ode to Joy" from his 9th Symphony.

http://www.youtube.com/watch?v=8r5Ieh0OuQY

No sound.  "Silent but deadly."    Hmmm, that didn't come out quite right.  LOL.  

The Imperial March from Star Wars.

Darth Vader's helmet does look like a penis glans.

that sound made by elephants.

I'm  with you girl, the  visual/audio combo is making me salivate and lubricate!!!!!  

Like the racking of a shotgun when you put in a shell.