Sounds like an opportunity for a SaaS company to provide text to speech service for companies, so all the "deaf" people can be subjected to upsells as well!
One thing I have wanted is a transcribing system so I can take voice calls in a chat interface.
Some systems e.g. doctors, banks often still insist on phone calls so if I can present as a phone call on their end but it is chat interface for me, that is ideal.
