Is there a smartphone that supports the TTY teletype service?

Episode 1131 (1:46:03)

Tim from Niagara Falls
smartphone

Tim wants to know if the TTY teletype service for phones could be used with more modern smartphones. Leo says that most smartphones do support it, including Apple iPhones. However, they are set up to be connected to an external TTY device. For a lot of people who have poor hearing, text messages and emails make this less important. There are still TTY operators, though. Here's a list of places with information on TTY: