In a movie or TV show, when a telephone rings is the sound coming from

  1. The actual telephone in the studio/location?
  2. A person from the crew creating a ringing sound?
  3. Post-production?

For example, I was watching an episode of Inspector Morse recently and Morse and Lewis where talking in their office. They were interrupted by a telephone ringing. What would have happened in that situation?

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    No one except crew can say, what of these did happen in a particular situation of a particular film.
    – Mouvier
    Commented Feb 13, 2018 at 10:59
  • BTW, though they're the same 'family' Morse would have been in stereo only & Lewis in 5.1, so the miking/mixing techniques would be different anyway. I've worked on Endeavour, but I'm struggling to think if I've been involved in a scene where this 'phone ring' type scenario would come into play. Can't think of anything yet.
    – Tetsujin
    Commented Feb 13, 2018 at 14:32
  • For a couple of shows (sitcoms) I've been involved in, we used your #2. Just a normal desk phone connected via a switch to a battery, and had someone off-camera trip the switch.
    – KlaymenDK
    Commented Feb 14, 2018 at 12:02
  • @KlaymenDK Were these multi-camera productions? Since these have studio audiences, I wouldn't expect them to do much in post-production other than editing.
    – Barmar
    Commented Feb 14, 2018 at 20:53
  • @Barmar yes, we had 2-4 cameras - but no live audiences.
    – KlaymenDK
    Commented Feb 14, 2018 at 21:54

2 Answers 2


It depends on the director and the crew's capability, as well as the actor's ability to act with or without an audible cue.

You can have a regular phone hooked up to a regular phone line or PBX and then ring it by calling it or it's extension.

  • Authentic sound
  • Not as easy to time
  • Provides cue for actors
  • Actors can listen and speak to person on other side - perhaps boths sides can be recorded, but also it encourages natural pacing even if only one side ends up on film.

You can have the actors act as though it rung, answer it, and add it in post production.

  • Timing is easier, but depends on actor's ability
  • Depends on actor's ability to convey a normal reaction to an unexpected sound
  • Sound timing can be very precisely managed in post

You can buy phones that ring on cue.

  • Similar to a real phone, but doesn't require a phone line or PBX
  • Specialized device, can't always choose the phone you want to use

You can buy devices that ring phones for you by applying the correct signals on the phone line.

  • Can use any standard phone, even decades old since the standard has been around for so long. This gives the director more options, and they can rent a phone from a prop company and don't have to modify it.
  • Some allow two phones and recording both sides.
  • Accurate ring - it's actually that phone's ring
  • Precise in-camera timing (depends on person activating it, but there are no delays like you might have with a PBX or real phone line)

For cell phones you can do nearly all the above as well.

You can use an active, real cell phone in the scene and call it.

  • Accurate sound, accurate screen images
  • Can't control timing as well
  • Have to be careful phone doesn't operate inadvertently at other times
  • usually a dedicated prop phone and phone number that's unpublished, with few to no apps and other notifications turned off
  • Can interact with it normally, including declining the call, adding additional callers to the call, etc
  • Can be used for texting as well
  • Must be managed more carefully - battery dying at the wrong time could scratch a take, and could take time to charge and reset the scene.

You can use a real cell phone but only pretend to answer it and add sound in the post.

  • More accurate timing of ring
  • Screen won't reflect what's happening (unless modified in post)
  • More common for older style analog cell phones which are harder to get attached to today's networks (late 90's or early 2000's period pieces)
  • If there's a display the actor may need to use the phone in a way and at an angle that prevents the display from showing on camera which can be done well, or poorly.
  • Depends on actors similar to the non-ringing regular phone above

You can use a fake cell phone with a screen dummy that allows both sound and CGI to be added in post so the display operates as the director wants it to.

  • Prop is more durable than a real phone
  • Timing of both display and sound very precisely controlled in post
  • Requires more post production, but with a green screen and markers on the display face this isn't the chore that it used to be.

A lot of this comes down to the effect the director wants, the capability of the actors, and the capability of the effects crews that would be involved. There are always other methods, this is just a simple overview.

  • Thanks. This is more in line with what I was after - an idea of the different methods used.
    – camden_kid
    Commented Feb 13, 2018 at 15:43
  • 1
    Another drawback with a real cellphone is the possible interference with audio equipment youtube.com/watch?v=IVoPOgPbRus Commented Feb 14, 2018 at 10:23
  • @ViktorMellgren Sometimes that is just the effect you want. I remember a scene from some crime-movie (can't remember which one) where the hero is sneaking around in a night-club, near the sound equipment on the stage. His cell-phone is on silent/vibrate, but when his girl-friend calls him, the buzz on the sound equipment gives him away to the bad guys.
    – Tonny
    Commented Feb 15, 2018 at 9:55
  • @ViktorMellgren That was associated with the older 3G GSM networks (So AT&T and TMobile) and while they still support and use 3G GSM it's much less a problem now that 4G LTE is rolled out from all providers across the US and most of the world.
    – Adam Davis
    Commented Feb 15, 2018 at 12:09

It could be any of the three methods, but the simplest method is to actually ring the phone, live on set, at the appropriate moment.

enter image description here

A telephone ringer is a device that any props department would have in their armoury. It just generates the correct voltage for the ringer circuit in the phone & is simply push-button activated.
If the actor answers the phone in the scene, no-one needs even worry about what line to release the button, the phone will naturally stop ringing, perfectly in sync.

This saves a whole slew of technical issues later, trying to match the sound & acoustics in post.

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    Interesting. Having done sound for film before, it seems to me this raises a whole bunch of technical issues. If you're doing it on set, how are you miking it? If you don't have a spot mike on it, then are you using the shotgun for dialog on it? If you do have a spot mike on it, why not just use foley or a sound effect library? Plus when you want to take out all the dialog for a translated version, how do you keep the ringing sound? Usually dialog tracks are center channel only, when we'd often rather pan the ringer. +1 anyway for the first sentence, but I'd rather do it in post every time. Commented Feb 13, 2018 at 14:12
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    One short film I did we needed Death's cell phone to ring. When shooting, he just paused for a moment and then picked it up and started talking. In post we used a virtual synth to create a cheezy sounding ring tone that was a fast version of that famous death march by that composer whose name I forget. It did get a laugh - although not a huge one. Oh yeah, we used a convolution reverb to give the ringer some space. Commented Feb 13, 2018 at 14:14
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    Interesting issues actually. First off, though I'm a sound engineer by trade & I do work in the tv/film industry, it's not on sound... so... maybe different needs for different things/budgets. TV, they ring the one in the room, so it will be on the dialog mics as well as ambients. Movies, I bet it's all in post. [I do far more TV than film, so I've never seen it done there]
    – Tetsujin
    Commented Feb 13, 2018 at 14:17
  • 1
    I wonder if TV shows get translated and dubbed a lot and then they have to add the ringer back in. Maybe it's not worth it in the TV market. I'm sure different types of films may do it differently. Wes Anderson might insist on the phone on set ringing, but a big budget action movie by Michael Bay probably has a lot more post production SFX and audio mixed in stems and all that razzle dazzle. Commented Feb 13, 2018 at 14:22
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    Now I wonder if things are different on opposite sides of the pond. All that aside, your answer has it right that all three (and maybe even other methods) are used. Probably the phone ringing on set is the simplest for many types of productions and others find other solutions. It's all art and there's no fixed process for art. Whatever has to be done to get the results needed seems to be how the film and maybe to a lesser extent TV industries work. Commented Feb 13, 2018 at 14:30

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