I refuse top leave my cell on vibrate during davening. Just think – if it does ring, some percent (say 5%) of my brain is busy with “Who called?”, “What did they want?”, “Do I need to call back?”, etc. That’s 5% that is not available for my concentration to daven. That’s not ok.
I’m an old hand at ignoring my phone – especially when I drive and especially when I daven. 🙂 But if it’s going to disturb you as you describe, then by all means, turn it off.
The Wolf