Q: Why is Terminal displaying my admin password?

I have tried everything to get my Mac (10.6.8) to play the startup chime.

Zapping the PRAM works during the initial startup, but with subsequent restarts there is no startup chime.

Usng terminal to type the following,   sudo nvram SystemAudioVolume=8  requires my admin password

which doesn't show as expected, but when typing a second command requires password, the password now shows on screen!

Any ideas what might be happening with the startup chime and the terminal??

Thanks