Off-hook tone

The off-hook tone (also receiver off-hook tone or off-hook warning) is a telephony signal used to alert a user that the telephone has been left off-hook for an extended period, effectively disabling the telephone line. See permanent signal.

North America

In the North American Numbering Plan a quad-frequency tone is used, consisting of frequencies 1400 Hz, 2060 Hz, 2450 Hz, and 2600 hertz, at a cadence of 0.1s on, 0.1s off ^[1]. It is played between the dial-tone timeout recording ("If you would like to make a call...") and the permanent signal holding state. A single burst of off-hook tone is sometimes used to indicate to a party that their call is being transferred, notably at 1-800-BELL-SOUTH (800-235-5768).

Some US CO switches, notably older GTE GTD-5s, utilize a single frequency tone, 480 Hz, known as "High Tone" for this purpose. In either case, the tone is substantially louder than any other signal which travels over a copper POTS circuit; loud enough to be heard across a room from an off-hook telephone.

United Kingdom

In the United Kingdom, a warbling signal sounding rather like an alarm siren is played (at steadily increasing volume) down a telephone left off hook on telephone lines provided by BT and many PABX extensions. It is sometimes referred to as a "Howler."

In some cases it is composed of the DTMF tones * and # played alternately.

Telephone lines provided by NTL/Virgin Media tend to use the American style tones, including a recorded message.

References

1. ^ Telcordia GR-506 § 17.2.8 Receiver-Off-Hook (ROH) Tone

External links

• High Tone
• Design schematic

This article related to telecommunications terminology is a stub. You can help Wikipedia by expanding it.v · Categories: Telephony signals Telecommunications term stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем написать реферат Chattanooga, Rome and Columbus Railroad Gerhard Hessenberg Look at other dictionaries: Off-hook — In telephony, the term off hook has the following meanings: The condition that exists when a telephone or other user instrument is in use, i.e., during dialing or communicating. Note: off hook originally referred to the condition that prevailed… …   Wikipedia off-hook —    1. In telephone operations, the condition existing when the receiver or handset is removed from its switch.    2. One of the two possible signaling states such as tone or no tone, ground connection or battery connection.    3. The active state …   IT glossary of terms, acronyms and abbreviations Hook flash — (sometimes labeled flash ) is a button on a telephone that simulates quickly hanging up then picking up again (a quick off hook/on hook/off hook cycle). This action can signal the telephone exchange to do something. A common use of hook flash is… …   Wikipedia Dial tone — For the G.I. Joe character, see Dial Tone (G.I. Joe). A dial tone (known in the British Isles as a dialling tone)[1] is a telephony signal used to indicate that the telephone exchange is working, has recognized an off hook, and is ready to accept …   Wikipedia Dual-tone multi-frequency signaling — One of the few production telephone DTMF keypads with all 16 keys, from an Autovon Telephone. The column of red keys produces the A, B, C, and D DTMF events. Dual tone multi frequency signaling (DTMF) is used for telecommunication signaling over… …   Wikipedia Reorder tone — The reorder tone, also known as the fast busy tone, is the congestion tone or all trunks busy (ATB) tone of a public switched telephone network. It varies from country to country; in the USA it is a dual frequency tone of 480 Hz and 620 Hz at a… …   Wikipedia Disconnect tone — A disconnect tone in telephony is a tone provided to the remaining party to a call after the remote party hangs up. Typically, the disconnect tone is a few cycles of the reorder or busy tone (e.g. in US), or between five and fifteen seconds of… …   Wikipedia Tone (linguistics) — Not to be confused with intonation (linguistics). Top tone ◌̋ ˥ …   Wikipedia On-hook — In telephony, the term on hook has the following meanings: The condition that exists when a telephone or other user instrument is not in use, i.e., when idle waiting for a call. Note: on hook originally referred to the storage of an idle… …   Wikipedia dial tone — noun A telephony signal, usually in the form of a sound, used to indicate that the telephone exchange is working, has recognized an off hook, and is ready to accept a call. Syn: dialling tone …   Wiktionary 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”