Is there an available device for providing an audible alert when the phone is off the hook?
The only such device I've found so far works only in the USA, as it requires the special off-the-hook signal used in the USA. It is called the Fonesitter, and is made by Command Communications, whose Technical Support department has assured me it will not work in the UK because it is incompatible with the off-the-hook signal used in the UK. It's available for about $10. It warns of off-the-hook and dead-line conditions in the USA.
I have read that in the UK, the off-the-hook signal used by BT is certain warbling sound. In the USA it is a harsh on-off-on-off... sound.
The UK version sounds a bit like a siren and gets progressively louder, its quite difficult to ignore.
The British Telecom off-the-hook signal is not noticeably audible from the telephone handset for people located more than a foot or two from the telephone.
Alone, that signal isn't adequate.
Is there an available device that can be plugged into the telephone wiring?
I've always found that siren very loud indeed. Maybe its a frequency thing. I have never been able to ignore it. The problem for me has been remembering what it was and where it was coming from - it is not easy to "locate".
Is there an available device to plug into the phone system of the house, to provide a very audible and/or visible alert that a phone is off the hook?
I'd like to stay focused on that question, rather than get sidetracked into discussing other people's hearing abilities.
[Some people may be able to hear the BT off-the-hook 'siren' signal far from the phone.
In my mother's case, she has left a phone off the hook many times, and has been unable to hear the sound.
It is a serious problem when she cannot be contacted because a phone is off the hook.]
I don't know of any product just for the off the hook signal but I would think an incoming amplifier would do the job, as it would increase the volume of all incoming sounds. Similar to this one `GEEMARC CLA30 TELEPHONE AMPLIFIER' Geemarc weblink. You can get them from Maplins for £ 19.99 Maplin link, but you can pick them up off ebay for a lot less like this one ebay link.
Did you ever find a solution to this 'no howler' problem? I've just learned from BT that when BT upgrades its exchanges, it is removing the howler from phone lines, including my elderly mother's local exchange. I need some sort of alert device for when she leaves/knocks her phone off the hook by mistake. Does anyone know of such a thing? Or even a handset that this built in?