I recall hearing a remark, in one place (stage-play venue?) that I was in, that cell phones and pagers should be turned OFF, not to silent (vibrating?) mode, because the vibration causes a buzzing nsound which can be heard. This does not seem to me to be a common request (although, in an orchestra I play in on a volunteer basis, I noticed at least one cell phone in use and am willing to let it remain on in silent mode). Have any of you out there heard of request to turn those things off as opposed to use of silent mode?