In the US, many people with hearing loss can use hearing aids to communicate.
But a growing number of researchers are using them to treat deaf patients.
Some are calling the technology speech therapy.
This is the second in a series of Recode segments exploring what it means to use speech therapy in deaf people.
Today: What is speech therapy, and how do people use it?
Recode senior writer Kara Swisher spoke to the people who are using it.