Speech-to-Speech (STS) is one form of Telecommunications Relay Service (TRS). TRS is a service that allows persons with hearing and speech disabilities to access the telephone system to place and receive telephone calls. STS enables persons with a speech disability to make telephone calls using their own voice (or an assistive voice device). STS uses Communications Assistants (CAs) – to relay the conversation back and forth between the person with the speech disability and the other party to the call.  STS CAs are specifically trained in understanding a variety of speech disorders, which enables them to repeat what the caller says in a manner that makes the caller’s words clear and understandable to the called party. The Commission’s rules ensure that STS users have the same ease of reaching an STS CA as users of the other types of TRS.

Who Uses STS?

Often people with speech disabilities cannot communicate by telephone because the parties they are calling cannot understand their speech. People with cerebral palsy, multiple sclerosis, muscular dystrophy, Parkinson's disease and those who are coping with limitations from a stroke or traumatic brain injury may have speech disabilities. People who stutter or have had a laryngectomy may also have difficulty being understood. In general, anyone with a speech disability or anyone who wishes to call someone with a speech disability can use STS. 

Using STS

A person can make an STS call from any telephone. Dial 711 to call the relay center and indicate you wish to make an STS call.  You are then connected to an STS CA who will repeat your spoken words, making the spoken words clear to the other party.  Persons with speech disabilities may also receive STS calls. The calling party calls the relay center by dialing 711 and asks the CA to call the person with a speech disability. STS users have the option of muting their voices during an STS call (so that the party to whom they are speaking hears only the voice of the STS CA, and not the voice of the STS user).  If you wish to use this option, please inform the STS CA to mute your voice for the other party to the call.  If you choose this option, the STS CA will still be able to hear what you are saying, and will re-voice what you say to the other party.

Mandatory Minimum Standards for STS

The FCC imposes mandatory minimum standards on providers of all forms of TRS, such as ensuring user confidentiality, making service available 24 hours a day, seven days a week, and answering 85 percent of calls within 10 seconds. We also impose certain additional requirements on STS providers.  For example, for each STS call lasting 20 minutes or longer, an STS CA must remain with a call for a minimum of 20 minutes before transferring the call to another CA. This allows for more effective communication for the STS user because the same CA stays on the call for a longer time. In addition: 

  • A STS CA may, at the request of the user, retain information from a particular call in order to facilitate the completion of consecutive calls. The user may ask the TRS CA to retain such information, or the CA may ask the user if he or she wants the CA to repeat the same information during subsequent calls. The STS CA may retain the information only for as long as it takes to complete the subsequent calls. 
  • STS providers must offer STS users the option to maintain a list of names and telephone numbers that the STS user commonly calls at the relay center. When the STS user requests one of these names, the CA must repeat the name and state the telephone number to the STS user. This information must be transferred to any new STS provider.
  • STS providers must have emergency call procedures in case a STS user calls 911.


Printable Version

Speech-To-Speech Relay Service (pdf)


Date Last Updated/Reviewed: 
Friday, January 10, 2020