Hearing Carry-Over, or HCO, is a Maryland Relay service for people who can hear clearly, but have difficulty speaking or being understood over the telephone.

How It Works

• The HCO user types his/her side of the conversation on a TTY (text telephone) or HCO phone.
• A Maryland Relay Operator voices the typed words to the other person.
• When that person speaks, the HCO user listens directly to what is said.

To Make an HCO Call

1. Dial 7-1-1 or 800-735-2258.
2. A Maryland Relay Operator’s greeting, including the Operator’s identification number, will display on your TTY or HCO phone.
3. Type "HCO PLS GA” (HCO Please. Go Ahead.) to indicate an HCO call. (You can also set up a Customer Profile, which automatically connects you to the appropriate Operator and lets him/her know your calling preferences.)
4. At the prompt, enter the number you wish to call. The Maryland Relay Operator will type "HCO on GA,” indicating that the HCO feature is on.
5. When the person you are calling answers, you can listen directly to him/her.
6. When it is your turn to respond, type your message for the Operator to voice to the other person. Remember to type "GA" (Go Ahead) when you are ready to hear that person’s response. Click here to see a list of commonly used TTY abbreviations.
7. If you would like to make another call, do not hang up. The Operator will remain on the line, ready to assist you.

HCO-to-HCO and HCO-to-TTY calling options are also available. To learn more about making and receiving HCO calls, download detailed instructions now, or call 800-552-7724 or 410-767-6960 (Voice/TTY) or 443-453-5970 (Video Phone) to request HCO user training.

HCO with Privacy

HCO users can ask their Maryland Relay Operator for HCO with Privacy when a call begins. With this feature, the Operator is unable to hear the other person’s spoken response to the HCO user.

Apply for an HCO Phone Provided by the State

HCO phones and other assistive telephone devices are available through the Maryland Accessible Telecommunications (MAT) program for qualified Maryland residents. Learn more about the MAT program.