View Full Version : sustained heartbeat


Michael Pace
November 8th, 2006, 01:44 AM
gang-- i searched on 'heartbeat', but i need a sustained rec method. Is there a stethoscope/mic interface i should be exploring for this? i need a sustained, non-looped heartbeat, needs to last convincingly for 30 secs or so

yrs,
MRP

Marco Wagner
November 9th, 2006, 10:28 AM
I can make that effect with my mouth, lol.

Greg Boston
November 9th, 2006, 11:33 AM
gang-- i searched on 'heartbeat', but i need a sustained rec method. Is there a stethoscope/mic interface i should be exploring for this? i need a sustained, non-looped heartbeat, needs to last convincingly for 30 secs or so

yrs,
MRP

You might try a PZM mic placed against your own chest just a little left of center.

I'm just wondering out loud why this wouldn't work based on the principles of PZM mics.

-gb-

Colin Willsher
November 11th, 2006, 05:31 AM
Did you sort yourself out Michael?

Does it really have to be a real heartbeat. Producers have long used synthetic effects for this purpose, particularly if has to be edge of the seat stuff.

Some methods are better than others but it's not difficult to get pretty close starting with a deep bass drum sample. Remove the attack with a short fade and use a Low Pass filter set very low. Boost the sub frequencies a little if necessary, then try to match your own (or your desired) heart rate, using a quieter repeat for every other beat. I have one if you need it but it was designed more as a 'pseudo' effect which quickens after about 20 seconds.

...but then maybe you just want to record a real heartbeat. Can't help there as I've never tried it but you'll need to keep the recording device absolutely still ;-)

Let us know what works for you.

Colin

David Scattergood
November 11th, 2006, 05:53 AM
I have a friend who would like his heartbeat recording and was finding out how I could reasonably achieve this. It's for a documentary project and possibly for a photo exhibition.
He was born with two holes in his heart (he's absolutely fine) and describes his beat as arythmic (much like my own as it happens) and also 'slooshy' - hence under these circumstances it would be a little dishonest to use a presampled heartbeat.
I have a Sennhieser ME66 mic and a Shure SM58 - not sure if I could get away with using these? I know one or two doctors; it might be possible that they could use their stethoscopes but how I would mic them up is another matter.

Colin Willsher
November 11th, 2006, 08:16 AM
I can't imagine a dynamic mic being much use for this application. Some sort of contact mic would surely be the way but I can't say I've tried this. Of course there is also ultrasound like that used in pre-natal scans, maybe this would be a place to start...

Fetal Dopplers and Baby Heart Rate Monitors (http://www.parenttime.com/babyarticles/fetaldoppler.html)

Good luck

Colin

Glenn Davidson
November 12th, 2006, 08:02 PM
I have a Earthworks QTC 1 omni and a Grace Preamp. I have used it for a project like you are describing. The mic has a very small diameter capsule and it is super sensitive. Any studio quality condenser microphone should give pretty good results. Like AGK 414, etc. Recording direct to digital, it will make a decent recording of the human heart.

Jim Michael
November 12th, 2006, 09:15 PM
The mic capsule of a Sanken COS-11 just fits in the rubber tubing of a stethoscope. You can disconnect the scope from the "y", insert the mic capsule and clamp with a couple of c-47s. Crank the gain up a bit and you should be able to get a decent recording. Try a medical supply place for an inexpensive scope.

David Scattergood
November 13th, 2006, 04:13 AM
Good idea Jim - I'll look around for one.
I'd have to tbuy a Sanken COS-11 though (not sure how much they retail for) and I'm not sure what a C-47 is?
Looks like there are a couple of options around this however.
Thanks.

Jim Michael
November 13th, 2006, 06:24 PM
You could probably adapt a different mic; I just gave the cos-11 as an example. cos-11 = $400. c-47 = clothespin.

Here's a sample with the cos-11: http://10squaredcorp.com/soundfx/hb1.mp3
Normalized and ambient noise reduction applied.

Seth Bloombaum
November 13th, 2006, 07:11 PM
...and I'm not sure what a C-47 is?...

We can't have clients hear us asking for clothespins, thus, c-47. I kid you not.

http://www.aeroconsystems.com/electronics/electric%20match%20making/clothespin.jpg

David Scattergood
November 14th, 2006, 02:48 AM
Well I never!
I have a few 'synthesized resin' C-47's upon my 'outdoor ventilation line system'. I'll pull a few of these off when the times comes!

Cheers folks.

Greg Boston
November 14th, 2006, 08:02 AM
Well I never!
I have a few 'synthesized resin' C-47's upon my 'outdoor ventilation line system'. I'll pull a few of these off when the times comes!

Cheers folks.

You don't want to do that, David. The synthesized resin version will quickly melt if used to clamp a gel in front of a light, which is what many C-47s do in production. Always use the original issue 'wooden' variety.

Just an FYI,

-gb-

David Scattergood
November 14th, 2006, 12:57 PM
Good point...I've always fancied au naturale over the synthetics...I'll get onto the missus about that one.
Quite a handy set of tools aren't they?
Cheers.

Michael Pace
November 15th, 2006, 07:59 AM
thanks everybody-- i've been out for a few days. Appreciate the ideas.

MRP