Bear with me for the whole story, please... It seems long but follows a liine of thought.
I got into the Echo scene simply to learn how to help My Quadriplegic Aunt become more independent in her entertainment choices. I bought the Echo and a Harmony Hub and tested them to figure out how best to set up a voice controlled AV environment that she could have personal control of... WORKS GREAT! Does so much more for her than my set up does, simply because she has cable TV set up, and All I have is DVD player, Playstation and internet available on my TV set up. Basically, I bought one, then bought her one as well. Hers is a dot only due to room and size... I have the full sized Echo... they work exactly the same.
Now, on to the Hearing impaired issue - - I hadn't even considered this an issue until I set up her system for her, but My uncle has hearing loss of a pretty significant nature, and he sometimes would like to watch something in the other room. Due to his hearing issue, he would love to set up headphones to sit and watch TV with so he doesn't need the volume on 11 to enjoy it... effectively overpowering half the neighborhood while watching TV... Their AV systems are almost back-to-back on the same wall, in different rooms... so distance doesn't make anything difficult... So here's where things get tricky... When he would be wearing the headphones to watch TV, he will not be able to hear My Aunt calling if she needs help. She has a Cell phone and they use a Baby monitor for normal daily coverage while he works in the other room, cooking and cleaning and such, he clips the monitor on and goes on about life. But he can't hear the monitor with headphones on... and no other indicators exist... like vibration or anything she can cause...
So... Here's what we did to help work this out. Of course he gets the headphone thing for sure! He desrves his entertainment too!... so we bought a single Hue Light bulb and a Bridge, and hooked up a lamp that sits next to his TV. When she needs something she can ask alexa to turn on "HIS LIGHT" and she does... alerting him visually so he can respond quickly and she will always have that available to her as a safety... no matter who is in the house. WE will eventually get a color hue bulb and give her scenes to choose to allow for grades of need as well... red alert being the highest form of course... the two of them will have separate echo dot's to control it with so he can re-set it and go back to watching TV if things are easily remedied.
All in all, this echo thing has a lot of potential for everyone whether for entertainment, accessibility or whatever comes up. Just thought I would share another way to use it for another issue cured.