The Silent Call Procedure
The Silent Call procedure is a unique program in the Massachusetts Enhanced 9-1-1 system that allows a caller who is unable to verbally communicate their emergency over the phone to receive the appropriate response.
If you need to call 9-1-1 and you are unable to speak for any reason, such as a physical disability, domestic violence or home invasion, follow these simple steps using a touch tone wireline telephone or a cell phone:
FIRST DIAL 9-1-1
Once the call is answered, indicate your need my pressing the appropriate number on your telephone. 
IF YOU NEED POLICE PRESS 1
IF YOU NEED FIRE PRESS 2
IF YOU NEED AN AMBULANCE PRESS 3
The 9-1-1 Dispatcher may ask questions that require yes or no answers.
PRESS 4 FOR YES
PRESS 5 FOR NO 
http://www.mass.gov/eopss/agencies/state-911/e911/about-e911/silent-call-procedure-2.html