Pentax 645D beep options
Digtial Discovery #10
Modern cameras beep a lot. The beeps may be useful for some photographers, but I imagine they cause more than a few raised eyebrows if you’re shooting in a temple, shrine, monastery, library or secret laboratory.
Help make the world a quieter place. Find the beep menu in your camera’s settings and deselect the various options.
Enjoy the crack of the shutter, and leave beeping to The Road Runner.
TRAVEL 67 : Chris Willson Photography 
If a discreet ‘bip’ from the camera is a problem, I can only imagine the difficulties you have run into with the ‘KATCHOPP-FLABAPPappp’ sound of the P67 🙂
Remember, you hear it well since the camera is right next you your head, but people further away are unlikely to notice. And audio focus confirmation is really convenient for manual lenses so you may want to consider keeping that one.
Already disabled in my K20D for the very same reason 🙂
With the K-x the beep when focus is locked is a blessing – on the other Pentaxes I try to keep it off!
PS I love the K-5 – it is even quieter than the K-7! Amazing!