h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

In the recent hit song "Blue" there is a vocal effect used during all the "dabba dees". It sounds like a synthesiser is playing along with the voice, quantising the pitch of the notes, but it has a vocal-like sound quality. The same effect was used in the chorus of Cher's "Do You Believe". How do they do that?

Syths do voices (but I haven't heard Blue yet).

They sample the voice into an expensive computer and fiddle about with the pitch. This sort of thing is very common in techno songs.

Are you positive? I was an R&D engineer at Fairlight, who pioneered audio sampling, in the mid eighties and I never heard anything that sounded like that. For one - when you change the pitch of the sample, you change the formants and to my ear the formants sound untouched. Is your answer definitive and based on some knowledge of what was actually used on those tracks?

I saw Tori Amos do a similar thing with a very high-end keyboard on PBS. I'm quite sure that's how they do it.

If she did it live, it definitely wasn't sampling! What you may have seen was a keyboard driving a vocal pitch modifier into a vocoder. Anyone know if such a thing exists?

Yes, but samplers shift vocal resonances, giving a chipmunk effect when higher and a frankenstein effect when lower. In this song, the vocal resonances remain faithful.

Isn't it the smae principle as a distortion pedal for an electric guitar except that it distorts voice?

Afraid not. A guitar distortion pedal just amplifies the signal until the electronics runs out of the ability to render the signal faithfully, at which point it does whatever the heck it wants to do. It adds a non-linear "game of chance" element to the process, which is why some people think one type of distortion sounds good while another thinks it is awful.

It clearly does exist, or else I wouldn't have seen her use one. Stands to reason.

Sorry, I'll make myself clearer....does anyone know the make and model of the "high end keyboard" you patently saw Tori Amos using? What are the features of that make and model? Do they include a vocoding and/or real time vocal pitch shifting signal processor?

*wandering back through old threads*

It still pretty much amazes me what the human voice (well.. -some- human voices) is capable of.. I was just thinking.. I wonder what instruments (other than the piano, perhaps) have such a huge range... Boggling.

'Nonnie

Just a guess, but I think it's done by by superimposing a wave of twice the frequency of the singers voice over the wave of the voice itself.
The tricky bit is varying the overlay with the singers voice - hence its use by performers who don't have much vocal range . Either that or they sing through the reed of a wind instrument.....

Though that might be easy for mice (we do have smallish mouths, you know ) it might get a bit difficult for.. uhm.. hoomans.

'Nonnie

It was a vocoder thing, listen to Fragments of Life by Roy Vedas or Believe by Cher for some other examples.
With current technology, it can be done in real time. To build one use some kind of DSP. The chips can now be got for not much money. Knowing how to set up the program for the DSP is another matter. Or program a computer soundcard to do a similar thing, pitch shifting, delays, filters etc.

The frequency shift is acomplished by adding bits back in or taking them out after the wave has been shortened or lengthened to change the pitch without dialating the time. This has a cycle setting that has to be changed to fit the particular voice. If you've ever heard thos voice disguising boxes, like they use on TV, they do the same thing, just not a clean.