Years ago, I had tried to wake up using the technology then available. The wake-up alarms for deaf and hard of hearing people, both the vibrating kind and the flashing light kind, failed to wake me up. I found that I slept through both alarms, as they were not powerful enough to overcome my tendency to be a deep sleeper.
Recently I tried again, with a new vibrating alarm clock. (Flashing light alarms were ruled out because I knew from past experience that I would likely just burrow under the covers to avoid the light.) Although the new clock is not powerful enough to wake the dead, it does well enough that I have not had any problems waking up since.
In addition, new door light signals and receivers that flash were installed. Again, I found the technology to be quite an improvement over what it had been years ago. When the doorbell is rung, the light flashes so brightly that it is impossible to miss.
Of course, the telephone is another device that I have a flashing light display for, both at home and in the office. When the phone rings, a light flashes and does not stop flashing until I have answered the phone or the phone stops ringing.
Plenty of other kinds of ALD devices are available as well. Other categories include baby cry lights, and entry alarm systems. The ones for deaf people tend to use light or vibration to alert users, while the ones for hard of hearing people usually rely on amplified sound.
If you would like to purchase an assistive listening device, the following resources are available here at About: Deaf and Hard of Hearing Product Vendors.
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