My mother lives with my brother and his wife, both who are profoundly deaf. The monitor we have 1) only works to make their lights blink if my mother is loud (she is not) or 2) just coughs badly.
Maybe it will take 2 products to do what you want. There are bed alarms that can be put under a person in bed, or under the rug when they step out of bed will sound. And another flashing or shaking of the bed one, that will go off when it hears a loud noise. Like I said, two different products that will work hand in hand.
in the baby section of target and like stores there are several products for babies that would also work for adults that alert the caregiver by sound and light. they range from $25 dollars up.
Well I just did a search for 'bed alert for deaf' and found all kinds of stuff. They have 'baby alerts' which work off sound, and in any hospital or nursing home, they have a pad that you can either put under the sheet on the bed or on the floor as soon as the person steps on it. They have bed shakers, flashing lights even sonic boom type stuff. Just got to do a little research on it.
Thanks.