Other Requirements for TTY Equipmentbr

Switching Between Voice and TTY Modes

• • This capability is necessary especially for silent calls, since call takers are required to first query the line by voice and then quickly switch to query the line by TTY.

  • This capability is also necessary for VCO and HCO, which are described below. VCO and HCO shorten the lengths of calls that would otherwise be conducted exclusively by typing.