I think this is more of a feature request than a question as I looked for a solution and didn't find one.

The Lync mute & unmute announcements are too disruptive to the call:

       "You've been muted, To unmute yourself press star six..." and "You are no longer muted ..."

it would be nice if there was an option to inhibit those messages (especially if I am the one that muted/unmuted myself)

There is no supported way to do this that I am aware of.

I'd certainly throw this suggestion up here: http://lync.ideascale.com/ - I too find this announcement disruptive.

I didn't see that anyone else had put the suggestion on ideascale, so I did it:

http://lync.ideascale.com/a/dtd/Disable-mute-unmute-announcements/781276-16285?submitted=1

Feel free to add your vote!