Here's a rundown of the basic things to consider when deciding on your alarm unit. These are the factors we took into account in our original testing of the alarms. See checklists for more information on what to look out for.
Some alarms come built into their own telephones, which you can use to replace your existing phone. However, if your current phone is easy for you to use - for example, if it has large numbers - then go for an alarm-only unit and plug your phone into it.
Making an alarm call
An alarm button on the unit itself is useful if you aren't wearing your portable trigger. When trying out units, make sure you can see and press the button easily - consider whether problems with your grip or a visual impairment might make this more difficult.
The unit will reassure you that the call is going through with lights, beeps, recorded speech or a text display. Make sure your unit does this in a way that suits your needs.
Always try out a portable trigger before you accept it - it's the most important part of the system. Make sure that its comfortable to wear and move about with, and that you can easily see and press the button.
Once you've had the system installed, try setting off the alarm from all over the house and garden. The operating range of the trigger needs to be good enough for you to use it wherever you are in your home.
If the trigger's battery is running low, it should send out a signal to let you know. Some alarm units will also send an alert to the control centre.
You can also have extra triggers fitted around the house to use alongside your main portable triggers, although you might have to pay extra for these. These might include wall buttons and pull cords. You can also get sensors that set off the alarm if something goes wrong, such as if they detect a fire or a gas leak.
Some triggers can even be used as controls for systems in your home - for example, pressing a button to open a door.
Some extra triggers need to be connected to the main unit by wires, while others work by radio instead.
Some alarms also come with a habit cycle. This means that the unit prompts you to press a button at certain programmed times, to let it know that you're still up and around. If you don't do this, it will dial the control centre or your family in case there's a problem keeping you from responding.
You should be able to talk the person answering your alarm call through a speaker, without picking up the phone. If your hearing is good, you won't have to be very close to the unit to do this.
If you have a hearing impairment, you will need to make sure your alarm unit has a volume control that can be turned up loud enough for you. The control centre should be able to adjust the loudness of their speech as well. You should also consider whether the unit's speakers have good enough sound quality for you to easily hear what's being said.
Type of speech system
Most alarm units can provide full two-way speech, like on a telephone. However, with some alarms the centre has to switch between speaking and listening, so that you have to wait before you can speak. The type of system you get depends on both the control centre and the alarm unit. Most alarms can do two-way or switchable speech, but the control centre may only be able to do one kind.
Answering ordinary calls
With many alarm units, its possible to answer an ordinary phone call by pressing the portable trigger. This means that if you're near the alarm unit, you can talk to the caller through the speech link rather than going over and picking up the handset.
Power cuts and other faults
It's worth thinking about what will happen if theres a power cut. Alarm units are generally plugged into the mains - they do have backup batteries in case the mains power fails, but its variable how long these will last.
The unit should give a warning when the power or phone line goes down. Again, this could be in the form of lights, beeps, speech or a text display. Some will also dial the control centre to let them know there's a problem.
Most units should be able to make an alarm call even if you've left the phone off the hook. However, not all will work if you've left an extension off the hook. Some can alert you by sending tones down the line.
Some older alarm units might not have been tested with newer services offered by telephone companies, such as voicemail and call diversion. If you make use of these services, check with the alarm centre or manufacturer that the system will work.
Next page: Who will receive your calls?