I am not too sure where to put this and apologise in advance if its in the wrong place
I had heard about 'silent calls' to the police. Apparently, when you are in danger and unable to speak you can still call them. I was under the impression that you could say nothing and they would still come to check you are okay. I only found out the other day that there was more to it. I have taken this from Thames Valley police website as it explains it a lot better than I could:
How the Silent Solution* system works:
A silent 999 call alone will not automatically bring help.
Please read the information below to understand how this system works:
WHEN YOU CALL 999: All 999 calls are directed to call centres and will be answered by BT operators. The BT operator will ask which service you need: Fire, Police or Ambulance. If you call 999 and don’t speak, the BT operator will be listening out for background noises (coughs, noises, taps on the phone, pressing 55, etc.) and will hang on the line for a certain period of time. If no requests are made and the BT operator believes the call needs to go through to an emergency service, it will always go to the police first. If no service is requested, but anything suspicious is heard throughout the process, the BT operator will connect you to the Silent Solution system.
The Silent Solution is a police system used to filter out large numbers of accidental or hoax 999 calls. It also exists to help people who are unable to speak, but who genuinely need police assistance. You will hear an automated police message, which lasts for 20 seconds and begins with ‘you are through to the police’. It will ask you to press 55 to be put through to police call management. The BT operator will remain on the line and listen. If you press 55, tap or make a noise, they will be notified and transfer the call to the police. If you don’t do any of the above, the call will be terminated after 45 seconds.
If you pressed 55, a police call handler will announce that you are through to the police.
If you can’t speak, you will be asked to tap the phone, make a noise or press 55. The police call handler will try a number of ways so that you do not feel under pressure to carry out just one prescribed action.
Only by pressing 55, tapping the phone, coughing, or making noise are you guaranteed a response to your call from a police call handler despite your silence. It is much easier to speak to the operator. But if you must stay silent, a mechanism has been provided that you can use to acquire help regardless.
Pressing 55 will not bring emergency services to your door and does not allow the police to track your location. By choosing to stay on the line, you are informing the police call handler that you might have an emergency that keeps you from talking, and they will do everything they can to determine your location so they can deploy officers to you.
The police call handler will try and engage with you, if you remain silent they will attempt to engage further and ask you to tap the phone if you are unable to speak; for example, yes and no questions can be asked by the call handler and answered using one keypad press for yes and two for no.
If the police call handler has concerns about your safety, they will continue to try to communicate through sound.
If you are able to speak without putting yourself in danger, the police call handler will ask just yes and no questions if necessary. In some cases, the conversation is led by the caller, who sometimes tries and speaks to the police call handlers in code, if for example the perpetrator has reappeared.
If you can say only one thing, please say your location. If you call from a mobile, we can pinpoint an estimate location but this does not narrow down enough to provide data we can locate you on.
Police call handlers can request subscriber checks and can carry out background checks to assist in locating you. This can depend on whether you have contacted the police before. Also, if your phone is registered to you, it could determine whether this will provide a potential location for you.
The police call handlers will deal with calls on a case by case basis, as each call is different, and the style of the call is adapted in line with the circumstances.
Silent Solution* = calling 999 without speaking, then pressing 55.