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Watching a "Columbo" episode recently (c.1971), it had a scene that I realized I used to see a lot in older movies and TV shows. A woman is talking on her rotary phone, when the person on the other end is suddenly cut off.

"Hello?" she says. Then she rapidly presses the hook switch of the phone several times, all the while saying "Hello? HELLO?"

How was pressing the hook switch repeatedly supposed to help? Was it supposed to restore certain kinds of lost connections?

I'm old enough to remember old phone technology, but we never used the hook switch on the phone other than to hang up the phone (or press once quickly for call waiting).

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I believe that by 1970 (at least in most places), this behavior did not really accomplish anything very useful, but would have been more of a habit.

However not too much earlier, operators would have been used extensively when completing calls. Repeatedly pressing the hook would cause a light in the office to flash, directing the operator to pick up. Since the operator might be able to assist with some types of dropped connections, the learned response to an unexpectedly dead line would be to call her in by cycling the hook.

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    This is the correct answer. The automated switching equipment that used pulse dialing wouldn't have reacted favorably to repeatedly pressing the hook switch - but the operators are signaled when someone did this on non-automated systems.
    – Adam Davis
    Aug 28, 2015 at 14:24
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    This seems like the best explanation as to why a movie character would hope that repeatedly pressing the hook switch as fast as possible might possibly restore her connection. (Of course it never actually works in any movie, ever....)
    – George Adams
    Aug 28, 2015 at 20:55
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    This is most likely correct. When I was in the Navy, serving in the Azores in 1993, the phone system there was given/sold to them by the US, but it was a phone system from the 1930's. This meant that all phones were rotary, (or pulse if they had buttons), as all calls I made were international, (home, to the US). the operator would place them for me manually, and they would very often get disconnected. when that happened it would piss me off and I'd start hitting the hook switch repeatedly to get the operator's attention as quickly as possible so they could dial the other side back.
    – KevinDeus
    Aug 29, 2015 at 9:14
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    Wow, this also explains why the button on some 80s and 90s phones that would hang up and pick up again (to access certain call features.) was called "Flash".
    – Todd Wilcox
    Sep 16, 2015 at 13:34
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Actually, on rotary phones (and maybe on some early touch-tone phones), that 'hang-up' lever, if pressed quickly and lightly, would send a signal that was equivalent to the dialing the number one (or however many times you pressed it). It was actually possible to dial that way if you were careful (why would this be needed? well, say you were a child, and some silly adult had applied a lock to the rotary dial...). I tried it once, back in the day when I first heard about it, and it DID work.

Anyway, back in those days, if one party accidentally pressed the 'hang-up' lever, and then immediately released it, the connection was not necessarily closed. Sometimes, pressing the lever again would have the effect of 'bringing the connection back,' even though it was still there. This became an issue again when call-waiting was introduced...you might think you've hung up on someone, but actually one of you is in 'on the other line' without actually talking to anybody, and 'hanging up' again, would 'restore' the connection.

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    Phreaking phones FTW.
    – Mazura
    Aug 28, 2015 at 2:48
  • @Johnny , that sounds reasonable. But would the standard procedure be to stab repeatedly at the hook switch? I can understand pressing it one time, but it seems like the TV/movie trope usually has the character clicking the hook switch 4-5 times as fast as possible (while saying "HELLO?")
    – George Adams
    Aug 28, 2015 at 5:09
  • When I was a child I realised that if you stab at the hook switch you could "lose" the call and then reconnect it with a further stab. When the call was lost the line would fall silent. There was noise on the line, so it wasn't dead, but neither party could communicate. A stab of the right duration, hence repeated stabbing, would bring it back. This was in the UK in the 90s.
    – Billy Back Bedroom
    Aug 28, 2015 at 7:47
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    Could it be a way to "buzz" the switchingboard operator instead? I.e. she would come online and you could ask her to kindly put the plugs back in or somesuch :-)
    – Edheldil
    Aug 28, 2015 at 8:15
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    why would this be needed? - Technically, it wasn't needed, it's just how dialing worked: en.wikipedia.org/wiki/Strowger_switch. When people (like yourself) began discovering how to hack the system it was replaced by CCITT protocols (first ss5 which got hacked using the famous cap'n crunch whistle then ss7 in use up to now which will probably be replaced by VOIP). The system was brilliantly simple - the pulses trigger relays to rotate and pauses cause the next relay to be selected.
    – slebetman
    Aug 28, 2015 at 9:22
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Phones can dial in three ways. Normal phones use Dual Tone Multiple Frequency (DTMF) dialing, where each number is a unique pair of two frequencies in a column x row manner. Cell phones use digital connections, but still use DTMF when the call is active so you can access an IVR.

Older phones use Pulse Dialing. Each number dialed actually breaks and makes the phone line connection n number of times. Real Rotary phones use this exclusively. Most normal phones have a switch that allow you to switch between DTMF and Pulse. This is still supported even in 2015. In the movie Hackers, one of the characters uses this to make an unauthorized call while in jail, by pressing the hook ten times really fast, to "dial" 0, to get the operator.

This break and make connection is also used to switch between lines, as in call waiting or placing a line on hold, or to set up a 3-way call. Some phones have a dedicated button for it called Flash.

The reason that people used to repeatedly press the hook is a combination of the above. Sometimes you are placed on hold or on the other line or to get the other side's attention.

Mainly this was before some modern phone signals were used, such as Calling Party Control. We all know this as the disconnect tone, and the off the hook tone. If you watch some shows, people used to take the phone off the hook to block calls from ringing. That behavior stopped when CPC introduced the off the hook tone, which is very loud and annoying. And more relevant to the question, the disconnect tone which tells one side that the other side has disconnected. Prior to CPC, you had no way of telling if the silence on the phone was silence or that the call was lost. The disconnect tone fixed that. People no longer had to toggle the hook to know you were hung up on, the BEEEEEP did it for you.

Oh the ever evolving PSTN technology.

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    The "flash" wasn't introduced until much later, and only involved automated switching equipment. The only time when pressing the hook switch accomplished anything at the middle or end of a call was when the switching equipment wasn't automated - when operators ruled the lines. They were signaled when the hook switch was repeatedly pressed. So this isn't a "combination of the above" it is merely a hold-over from the time when switching wasn't automated.
    – Adam Davis
    Aug 28, 2015 at 14:27
  • Because it is so hard to distinguish between no connection/faulty equipment etc. and no one talking, most modern telephone systems (especially IP based digital ones) use comfort noise.
    – Josef
    Sep 15, 2015 at 14:43
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I can confirm that (cde & BowlOfRed's answer) - the other answers aren't quite right because the technology started changing so rapidly in the 60's and 70's after the transistor was invented and finally found its way to the phone system. Everyone was used to hitting the phone hook repeatedly to hang up - it took a while for this old habit to die out.

I was born in the 50's and actually used those phones back in the day. Hanging up back then frequently didn't break the connection because everything was done by switchboard operators. I always thought it was weird that I could hang up and then pick up the phone 5 minutes later and still be connected to the other phone. Hitting the phone hook rapidly flashed a light on the switchboard operator's panel, which attracted her attention. She would manually pull the cord out of the panel, and the call would finally be disconnected.

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  • So if you're trying to re-establish a connection, why would you signal the operator to disconnect the call?
    – Johnny Bones
    Aug 28, 2015 at 16:53
  • @JohnnyBones I wasn't trying to re-establish the connection when I picked up the handset. I was testing to see if the call was still connected.
    – Bill
    Aug 28, 2015 at 19:21
  • "Hitting the phone hook rapidly flashed a light on the switchboard operator's panel, which attracted her attention. She would manually pull the cord out of the panel, and the call would finally be disconnected." The question is about rapidly hitting the handswitch, which you state in your answer is a signal to disconnect the call.
    – Johnny Bones
    Aug 28, 2015 at 19:48
  • Back then, we thought of hitting the hook repeatedly as a sort of reset button - we did it when things were wrong with the phone or to make sure the call got disconnected. To hang up, we usually just put the receiver on the phone base and walked away. It didn't matter if the call was still connected, because eventually the switchboard operator would see the light on her panel for that cord had been on too long and she would listen in briefly for dead air. If no one was talking, she'd pull the cord.If we wanted to hang up and call someone else right away
    – Bill
    Aug 28, 2015 at 20:02
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    In a panic situation, hitting the hook sometimes worked to restore a disconnected line. My mother used to be a switchboard operator and I watched her work. She would "pull the plug" to disconnect a call, but because the numerous criss-cross cables on the panel were confusing, she would pause before releasing the cable with her hand, in case she pulled the wrong cable. If the customer flashed the light, she would reconnect the call.
    – Bill
    Aug 28, 2015 at 21:53

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