Possible Clues:

• Grapeshot? That was used to send someone a message!
• Electronic messaging device
• Rotten grape? It has an old funny ring to it perhaps!
• Electronic device beginning to ring after quiet period
• ''Grey's Anatomy'' prop
• "We can seat you now" buzzer
• On-call attachment
• Doctor's clip-on
• Beeping device
• "Your table's ready" gadget