It started about 2 years ago with a humming sound. Now it's all kinds of sounds/noises. I noticed last night when we went to a Christmas concert at church that she stopped making the noises when the music was playing. I wonder if it's a calming mechanism and that's why she doesn't do it when the music is playing?
Music can be so effective for people with Alzheimer's that there are people who specialize in music therapy. I'd suggest that you make music as much a part of her environment as possible. Experiment with different types (naturally, the music playing at church should be included).
Observe her response to different types of music and adjust accordingly. You're on to something, so go with it. Often that's what we have to do - experiment. When something works keep it up. When it doesn't, try something else.
Good luck,
Carol