How do I imitate voice over a phone? at DVinfo.net

Slava Barouline · December 16th, 2007, 10:04 AM

Hi

There is a phone conversation in my short film

How do I imitate voice over a phone?

Thanks
Slava

Richard Alvarez · December 16th, 2007, 10:22 AM

What is your editing system? Most NLE's will have a 'phone filter' in their audio suite of effects.

Emre Safak · December 16th, 2007, 10:30 AM

Bandlimit the signal to 8KHz and quantize it to 8 bits.

Slava Barouline · December 16th, 2007, 06:30 PM

Quote:

Originally Posted by Richard Alvarez

What is your editing system? Most NLE's will have a 'phone filter' in their audio suite of effects.

Vegas 8

I will have a look - didn't think of it
;-)

Slava Barouline · December 16th, 2007, 06:31 PM

Quote:

Originally Posted by Emre Safak

Bandlimit the signal to 8KHz and quantize it to 8 bits.

I will give it a try

Thanks

Andre Theelen · December 18th, 2007, 03:27 AM

You can take the bandwidth down even further.
If I'm not mistaken the spectrum of an analog phone channel is about 300-3300 Hz.

Just play around with the upper cut-off frequency of the filter untill you get the effect you like.

Regards, Andre.

Paul R Johnson · December 18th, 2007, 07:33 AM

300-3000 ish is pretty effective for the phone systems in europe - even though they do nowadays do a bit better. What is needed is the sound people 'think' telephones produce, not what they 'really' do!

Dale Baglo · December 18th, 2007, 11:25 PM

I usually put a hi pass filter and a low pass filter on, so that it's mostly 200 to 3000 K. I might even bump up the 1K a bit. Finally, I put a fair amount of compression on to squeeze it a bit. If that doesn't do it, try using the worst mic you have, then repeat the above EQ and compression steps.

Rob Knoll · March 24th, 2011, 12:51 PM

I have a super low tech way of doing it, depending on what sound you are looking for.

1. Put a phone on speakerphone mode.

2. Point your microphone at it.

3. Call the phone from another room, and have your talent deliver their lines.

Tada!

This is good for intercoms, and telephones. Again, it depends on exactly what you need, but this fits the bill in most cases.

Enjoy!

Battle Vaughan · March 24th, 2011, 07:55 PM

There is a free telephone VST filter listed on the Audacity site, I assume it would work in any program that accepts vst plugins: VST Plug-ins - Audacity Wiki

Jonathan Levin · March 27th, 2011, 11:05 AM

I haven't done this and I don't know if it could even work, but why not sacrifice a phone to handset cable and splice that to a another cable going into the recorder?

Anyone tried this?

Jonathan

Greg Miller · March 27th, 2011, 11:22 AM

You wouldn't need to sacrifice anything. Just unscrew the ear cap, remove the receiver, and attach a cable with alligator clips to the two wires feeding the receiver.

You will also need an audio isolation transformer between the telephone connections and the recorder, because the telephone is not grounded and not exactly balanced, either. It will have a lot of ground loops, and a significant amount of DC voltage, compared to your local ground.

However, doing the above will get you a clean recording of the signal that goes to the receiver, and ignores the acoustical characteristics of the receiver itself. So that recording might not be as realistic as you hope.

But then again, different telephones, with different electrical networks inside, and different receivers, all sound different anyway. You aren't necessarily trying to get a realistic recording of anything. You are trying to create a realistic-sounding illusion of a telephone call.

(At any rate, traditional telephone networks did pass about 350 - 3,000 Hz, as a starting point.)

Jonathan Levin · March 27th, 2011, 11:48 AM

Greg,

Great info.

Jonathan

Greg Miller · March 27th, 2011, 03:38 PM

Thanks, Jonathan.

BTW, it occurs to me that the "telephone sound" is a lot more diverse today than it was 20, 30, 40 years ago.

The original telephone sound came from the raspiness of the single-button carbon microphone, as well as the tinny resonance of the receiver and the narrow bandpass of the telephone network.

In newer phones, the carbon mic has been replaced by an electret, which is cleaner and has better HF response. Newer phones have better receivers. Both those changes improve the quality so the "telephone" sound is less pronounced. OTOH, we now have cell phones with all the digital artifacts caused by inadequate digital bandwidth, so that adds a new and different dimension to "telephone sound."

So, before you start, you need to figure out what era's telephones you are trying to imitate!

December 16th, 2007, 10:04 AM	#1
Slava Barouline Regular Crew Join Date: Apr 2007 Location: Canberra, Australia Posts: 47	How do I imitate voice over a phone? Hi There is a phone conversation in my short film How do I imitate voice over a phone? Thanks Slava

December 18th, 2007, 11:25 PM	#8
Dale Baglo Regular Crew Join Date: May 2006 Location: Victoria, BC Posts: 64	I usually put a hi pass filter and a low pass filter on, so that it's mostly 200 to 3000 K. I might even bump up the 1K a bit. Finally, I put a fair amount of compression on to squeeze it a bit. If that doesn't do it, try using the worst mic you have, then repeat the above EQ and compression steps. __________________ Need a narration? www.dalebaglo.com

March 24th, 2011, 12:51 PM	#9
Rob Knoll Regular Crew Join Date: May 2010 Location: New York Posts: 51	Re: How do I imitate voice over a phone? I have a super low tech way of doing it, depending on what sound you are looking for. 1. Put a phone on speakerphone mode. 2. Point your microphone at it. 3. Call the phone from another room, and have your talent deliver their lines. Tada! This is good for intercoms, and telephones. Again, it depends on exactly what you need, but this fits the bill in most cases. Enjoy!

March 24th, 2011, 07:55 PM	#10
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Re: How do I imitate voice over a phone? There is a free telephone VST filter listed on the Audacity site, I assume it would work in any program that accepts vst plugins: VST Plug-ins - Audacity Wiki

March 27th, 2011, 11:05 AM	#11
Jonathan Levin Major Player Join Date: Apr 2008 Location: Chicago, Illinois USA Posts: 692	Re: How do I imitate voice over a phone? I haven't done this and I don't know if it could even work, but why not sacrifice a phone to handset cable and splice that to a another cable going into the recorder? Anyone tried this? Jonathan __________________ "Fearless Fernando Hernandez: A Fighter's Journey"" Jonathan Levin Photography & Video

December 16th, 2007, 10:22 AM	#2
Richard Alvarez Inner Circle Join Date: Sep 2002 Location: San Mateo, CA Posts: 3,840	What is your editing system? Most NLE's will have a 'phone filter' in their audio suite of effects.

December 16th, 2007, 10:30 AM	#3
Emre Safak Trustee Join Date: Feb 2004 Location: Brookline, MA Posts: 1,447	Bandlimit the signal to 8KHz and quantize it to 8 bits.

December 18th, 2007, 03:27 AM	#6
Andre Theelen Regular Crew Join Date: May 2007 Location: Netherlands Posts: 51	You can take the bandwidth down even further. If I'm not mistaken the spectrum of an analog phone channel is about 300-3300 Hz. Just play around with the upper cut-off frequency of the filter untill you get the effect you like. Regards, Andre.

December 18th, 2007, 07:33 AM	#7
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,016	300-3000 ish is pretty effective for the phone systems in europe - even though they do nowadays do a bit better. What is needed is the sound people 'think' telephones produce, not what they 'really' do!

March 27th, 2011, 11:22 AM	#12
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: How do I imitate voice over a phone? You wouldn't need to sacrifice anything. Just unscrew the ear cap, remove the receiver, and attach a cable with alligator clips to the two wires feeding the receiver. You will also need an audio isolation transformer between the telephone connections and the recorder, because the telephone is not grounded and not exactly balanced, either. It will have a lot of ground loops, and a significant amount of DC voltage, compared to your local ground. However, doing the above will get you a clean recording of the signal that goes to the receiver, and ignores the acoustical characteristics of the receiver itself. So that recording might not be as realistic as you hope. But then again, different telephones, with different electrical networks inside, and different receivers, all sound different anyway. You aren't necessarily trying to get a realistic recording of anything. You are trying to create a realistic-sounding illusion of a telephone call. (At any rate, traditional telephone networks did pass about 350 - 3,000 Hz, as a starting point.)

March 27th, 2011, 11:48 AM	#13
Jonathan Levin Major Player Join Date: Apr 2008 Location: Chicago, Illinois USA Posts: 692	Re: How do I imitate voice over a phone? Greg, Great info. Jonathan __________________ "Fearless Fernando Hernandez: A Fighter's Journey"" Jonathan Levin Photography & Video

March 27th, 2011, 03:38 PM	#14
Greg Miller Trustee Join Date: Jan 2011 Location: Pennsylvania Posts: 1,786	Re: How do I imitate voice over a phone? Thanks, Jonathan. BTW, it occurs to me that the "telephone sound" is a lot more diverse today than it was 20, 30, 40 years ago. The original telephone sound came from the raspiness of the single-button carbon microphone, as well as the tinny resonance of the receiver and the narrow bandpass of the telephone network. In newer phones, the carbon mic has been replaced by an electret, which is cleaner and has better HF response. Newer phones have better receivers. Both those changes improve the quality so the "telephone" sound is less pronounced. OTOH, we now have cell phones with all the digital artifacts caused by inadequate digital bandwidth, so that adds a new and different dimension to "telephone sound." So, before you start, you need to figure out what era's telephones you are trying to imitate!