Comments on: Mechanically-Achieved Audio Time Compression/Expansion

By: Matthew Florez

Matthew Florez — Wed, 07 Dec 2016 20:43:20 +0000

According to Wendy Carlos, on the website linked above, she suspected that the voice of HAL (Douglas Rains) in Kubrick’s 2001 was processed through one of these devices.
She was able to confirm that with Kubrick when she worked with him later.

By: Scott

Scott — Sun, 19 May 2013 20:19:50 +0000

This concept was also used in the GRM electronic music studio, as the universal phonogène. It was used by a number of composers from probably the mid 60s to the mid 70s. I can’t be completely sure, as the technical aspects of such pieces usually aren’t usually discussed in detail, but Bernard Parmegiani’s Capture éphemérè (1967) seems to be a great illustration of this. It’s basically a mechanical implementation of an early pitch shifter, similar to the Eventide H-910.

By: Bill Brophy

Bill Brophy — Thu, 16 May 2013 05:50:31 +0000

In the late 60s or early 1970 I took a course at Ohio University called Listening. It used a mechanical T/P device like the one described here. Day 1 we listened to a lecture (recorded and boring) at real speed. Took a test about it afterward. Each day, a different lecture with the playback at increased speed. Each day, a test. Soon we were at 10 or maybe even 15 times or more the real speed. The time was reduced but normal pitch was retained. Nothing could really be understood by then on the surface, but … my test scores got better and better each day. They started in the 50% range and ended up at the higher speeds near 80%. In essence we had learned to “speed listen”.

At the higher speeds a lot of the speech was really cut out by the device, but the brain was able to suck up the material. The speed listening skill was useful later in my audio production and editing days.

By: Ian Wayne

Ian Wayne — Sat, 23 Feb 2013 16:33:51 +0000

I remember repairing an Eltro at Universal City studios in the early ’80’s. They were occasionally used on dubbing stages, and they did actually work pretty well (within a certain range), if they were set up correctly. The Audio Cyclopedia 2nd. edition has a good description of the theory behind the device.

By: chris

chris — Sat, 23 Feb 2013 13:28:47 +0000

In reply to tam cooper. awesome! thanks for sharing Tam. c.

By: tam cooper

tam cooper — Sat, 23 Feb 2013 12:27:39 +0000

there is an article on the Wendy Carlos site about something very similiar:

http://www.wendycarlos.com/other/Eltro-1967/Eltro-1967.pdf