Receiver 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 accidentally left off-hook for an extended period, effectively disabling the telephone line.

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.

Receiver Off-Hook Tone is 1400 Hz, 2060 Hz, 2450 Hz and 2600 Hz at 0 dBm0/frequency on and off every .1 second. On some older space division switching systems Receiver Off-Hook was 1400 Hz, 2060 Hz, 2450 Hz and 2600 Hz at +5 VU on and off every .1 second. On a No. 5 ESS this continues for 30 seconds. On a No. 2/2B ESS this continues for 40 seconds. On some other AT&T switches there are two iterations of 50 seconds each.

Category:

Education

Tags:

• telephone
• sounds
• off
• hook
• tone
• phreak
• att
• ma
• bell

[joebenavides12345678]

lyrics plz

[i3igpete]

god this used to scare the shit out of me as a kid

[misterrailroadman]

Is this a howler tone or is the howler tone something else?

[holyinpure]

aaaaah!!! my ears are about to explode!!!

[holyinpure]

@cobrachoppergirl lol

[Florey96]

@i3igpete Me too haha

[cobrachoppergirl]

good beat, easy to dance to, i give it a 5

[joebenavides12345678]

@Washu1973 thanks XD

[Washu1973]

@joebenavides12345678 beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep beep

[misterrailroadman]

I read that the other phone off the hook tone that sounded like a siren or whistle was so called a howler tone. Do you'll have any recordings of that or does Evan Doorbell?

[misterrailroadman]

@i3igpete It did me to