When two people need to communicate by telephone but do not speak the same language, they may benefit from telephone interpreting. This service involves a person translating the telephone conversation for two people who do not have a language in common, though it also is used by people who have a hearing impairment and rely on sign language to communicate with people who don't sign. An interpreter who wants to do the job well needs an excellent grasp of both of the languages involved in the conversation, as well as top-notch communication skills for helping both parties understand the communicated information. With good telephone interpreting, the parties to the conversation may even rely on the interpreter for information about non-verbal communication, such as changes in tone.

Conversations between two people who do not speak the same language are always a challenge, but conducting such conversations over the phone can prove even more difficult. Without face-to-face cues, a person cannot use body language to help him decipher the meaning of the other party’s words and, even if he does know sign language, he may not have the necessary equipment to see a person's signed telephone conversation. To overcome this challenge, a person may seek the help of a telephone interpreter. This person listens to the conversation of two or more people who speak different languages and then provides translation. Telephone interpreting generally proves easiest when just two people are involved in the conversation, but it also may prove useful in some conference-call situations.

A telephone interpreter usually works by listening in on a telephone conversation and waiting for one speaker to finish what he wishes to say. Once the speaker is finished talking, the interpreter relays what the speaker said to the listener. The listener may then take a turn to speak and, when he is done, wait for the telephone interpreter to relay his words to the initial speaker. It is important to relay the exact conversation and take into account the tone of the speaker, so a telephone interpreter must have excellent skills in both languages.

A person needing telephone interpreting may find help from a variety of organizations, depending in part on the reason for the need for assistance. For example, he may take advantage of this service through a government or non-profit agency. Some for-profit businesses and independent interpreters also may provide this service. In some cases, hospitals and insurance companies provide or contract for telephone interpreting services. A company that does a lot of business with foreign organizations may maintain its own staff of telephone interpreters.