Ah... vocal formants!

I've seen discussion about use of the Electro-Harmonix Talking Machine effect pedal. The Talking Machine moves between two vowel sounds, or allows fixing upon just one.

A wah pedal also allows moving the frequency, or of just moving the pedal to one position and leaving it there. However, even though it sounds similar to a human voice, it doesn't quite get there.

So, what's the problem?

The problem is that a normal wah pedal only has one filter peak... while the human voice has more than one peak for any given vowel, called "formants." Those peaks in a human voice stay the same, even when a person moves the pitch up and down. The pitch comes from the vocal cords, but the resonances come from other parts of the vocal tract, including the tongue and how open one's mouth is.

Although there are more than two formants for any given vowel, two is enough to make a vowel unmistakeable.

The Talking Machine actually has two wah envelope filters. (An envelope filter is a filter which moves from one setting to another based on how loud a sound is. With a plucked string, the volume envelope, or shape, starts loud and then moves down to nothing. With the filter moving along with the envelope, and with the loudest setting being an "aaa" and the softest setting being an "ooo," you'll get an "aaaooow" with the plucking of a string.) Although a normal single envelope filter will get something like a vocal sound, the Talking Machine really nails it.

The Talking Machine also has a setting where the filters stay in the same place. There's a few videos (including the imcomparable Amethyste's) using the Talking Machine for a male tenor voice.

Talking machines are expensive, though, and you're paying not just for a pair of fixed filters, but for the presets which turn two formant filters into paired moving formants to simulate human vowel movement. That can be pricey.

However, you don't have to spend that much if you're only going to be doing a couple of vowels.

Two cascading Q-Zone pedals, which are each a fixed wah (non-moving, other than setting the knob), can be set up to cascade, one into the other. The first box will be set to the higher formant, and the second box to the lower of the two formants. The second box will have more of an audible effect, being as it filters down the spike of the higher formant, just as the lower formant is louder than the higher in the human voice.

So, how to choose the frequencies?

I normally do it by ear, find setting the second box inline, and then going back to the first and dialing it in. However, the Wikipedia page on formants lists combinations of frequencies for various vowels.

http://en.wikipedia.org/wiki/Formant

I also thought the following was interesting, although I have the mechanical aptitude of a gorilla with a hammer and a hardboiled egg. *laugh* This section of the page on formants (great reading, incidentally) includes a proposed dual wah pedal, a Talking Pedal instead of an automatic Talking Machine.

http://www.geofex.com/Article_Folders/wahpedl/wahped.htm#twowahs

I imagine that using two parametric filters with adjustable Q (width of the peak of the filter) would also let one do formants, but I haven't tried this myself.

Adding a little bit of reverb can smooth out the edges on these sounds, adding just the right kind of resonance to really make it gel.

Of course, the richer the sound of your instrument, the more there is for the filter to work on. A pure sine wave voice might need a fuzz pedal before heading into the filters.

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In addition to using fixed wahs, I also regularly use effects/multieffects like the Electro-Harmonix POG2 (multiple octave generator, along with a filter), the Korg PX5D (which has both a fixed wah and a fixed filter, as well as many other effects, all in the size of a cassette tape), and the Boss ME-50B (quite a few filter options, and an amazingly versatile pedal which, although designed for bass, I use regularly as a "synth" pedal for guitar). 

Now I'm jazzed to ask a friend of mine, with more soldering skills than my non-existent ones, to build me a pedal with two fixed wahs or resonant filters in sequence. I figure I can mark the formant settings around the knobs with permanent color marker, so I can look down and see the pairings and easily set them on the fly. I have a small shelf attached to the mic stand upon which the instrument is mounted, so it would be close at hand.

(Now that I'm thinking about it, the PX5D's second filter (in the modulation section) is just a fixed frequency low pass filter with no resonant peak, but I suspect that by using TALk 4 ("yeah") and setting the sensitivity  to its most sensitive, I can get the lower resonant peak, while using the Vox Fixed Wah in the section feeding to get the first formant's resonant peak. Either that, or I can use FILTUP2 for a resonant peak. That would allow all this in a multieffect I already have on the small shelf mounted on my mic stand.)

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Anyone else doing filter experiments?

Hmmm - sort of kept this to myself until now.. A WONDERFUL project from a long time ago (1976) which I built, and went on to build several variants - used the core concept in projects at the Medical School, was the basis of "vocal" breath sounds to enable infants to synchronise their breathing with ventillators... I have completely redesigned it many times so as to allow voltage control rather than ganged potentiometers, and used theremin circuitry to create a 3d space-field joystick, X and Y controlling formant, Z controlling volume.. My last design bore little resemblence to the article - but the idea and understanding came from the original article, it was one of those articles that I learned a lot from and inspired years of (intermittant) experiments.

The design is easy to build and gives quite good formant synthesis.. Not as "good" as the TM by a long way (it only controls 2 formants, whereas the TM has many more) but nicer IMO, if (alas) weaker..

http://www.synthdiy.com/files/2010/chatterbox-1976.pdf

The generator front-end is, IMO, clumbsy - But the filter circuits are incredibly simple and quite effective - Its a great starting point from which to explore vocal / formant synthesis.

Fred.

As far as I know, I was the person who introduced the Electro-Harmonix TALKING MACHINE to the theremin community. It was a novelty for a few months, a lot of people bought one, and then interest in it dropped off.

WHY?

The diphthongs (two or more vowel sounds together: eeeaaaooooo, ooooeeee, etc.) are great but they only work for comic FX. Gordon Charlton used the TM in this way very successfully but not many people are interested in that kind of sound, particularly in the "precision" theremin community. They are looking for a more convincing, moving, dramatic timbre.

Of the nine presets available, the only single formant that seems to work with the theremin is the open "AH" (12 o'clock on the VOICE dial), all the other sounds are too nasal, too twangy, or too pinched, and sound sort of cartoonish and silly (which is O.K. if that is what you're looking for).

While the open "AH" is quite convincing as a lyric baritone/tenor, what it lacks is the quality known as "spinto". This is Italian word for "pushed" and refers to that over-the-top, exciting, dramatic quality that you get from tenor high notes. This is what people love most about the tenor voice, but it is the very quality that is lacking in the TM. As you play higher, the TM does not become a powerful, dramatic, high tension "spinto". Instead it morphs into a "falsetto" countertenor. 

For precision players, most of the time an effect is a means to an end, an enhancement, and is not the real focus of what they are doing. For the FX and experimental communities, often the effect IS the end.

There are some thereminists who use the TM much of the time. I believe Sarah Rice uses it a lot, and I noticed that thereminist Rob Schwimmer used it when he played on CBS SUNDAY MORNING. 

"The design is easy to build and gives quite good formant synthesis.. Not as "good" as the TM by a long way (it only controls 2 formants, whereas the TM has many more) but nicer IMO, if (alas) weaker.."  - FredM

Wow, nice paper Fred, thanks!  From the glory days of 4000 series CMOS, 741 op-amps, strong know-how, and some elbow grease.

I plan to do some vocal research for Theremins and such (once I get out of this bottomless processor design rut).

Coalport wrote,

Of the nine presets available, the only single formant that seems to work with the theremin is the open "AH" (12 o'clock on the VOICE dial), all the other sounds are too nasal, too twangy, or too pinched, and sound sort of cartoonish and silly (which is O.K. if that is what you're looking for).

That makes sense, given that most sung music which uses only a vowel is an "ah" sound. Unless you're a huge fan of "Hocus Pocus," by Focus. *laugh*

Coalport wrote,

For precision players, most of the time an effect is a means to an end, an enhancement, and is not the real focus of what they are doing. For the FX and experimental communities, often the effect IS the end.

The great irony is, the thermin is often that "effect" fwhich gets tossed in. Like Dr. Tanner noted about his gigs for electro-theremin, he got used when it was about space, ghosts, or someone being drunk.

I think the two major soundtracks it got used for in the past decade were "Ed Wood" and "Mars Attacks!," both Tim Burton films.

Theremin playing has always been considered an effect by almost everyone outside of a virtual handful of players. At least one article I've read here about one historical theremin talked about the antenna being replaced with something (lightning bolts, IIRC) which was terrible for actual precision playing, but great for appearance.

Coalport wrote,

There are some thereminists who use the TM much of the time. I believe Sarah Rice uses it a lot, and I noticed that thereminist Rob Schwimmer used it when he played on CBS SUNDAY MORNING. 

I suspect that they used them to escape from that "sci fi" vibe which is instantly conjured up for the average person  by the theremin's sound. As "cartoony" as one might think the Talking Machine, it's less of a caricature than the theremin.

Honestly, that's why I started experimenting with different timbres. And it works in terms of instant acceptance. I have one patch on the PX5D which sounds like the Chinese erhu, a two-stringed fiddle. A Vietnamese friend came over and heard it from outside. She came in and said, "I heard you playing the đàn gáo (the Vietnamese equivalent)! Where is it?" It's not so much about the sci fi aspect, at least I believe.

(Wow, I am wordy! I just saw how long my original post was! *laugh*)

Since the theremin is already an "effect" in the minds of most listeners, it would seem that the people who regularly use the Electro-Harmonix TM are adding an effect to an effect in hope that somehow they can turn the theremin into something other than what it is.....AN EFFECT!

What is a theremin?

For many people the definition of a THEREMIN is any sound that is reminiscent of the type of "spooky" FX used in SciFi, horror and suspense films of the 1950's. They don't care whether what they are hearing is a genuine heterodyne instrument or not, it could even be a keyboard synthesizer program. If it sounds more or less like a theremin, IT'S A THEREMIN. 

The musician hired for the MARS ATTACKS soundtrack was Los Angeles thereminist Ed Sussman. As I understand it, there is very little of Mr. Sussman in the final mix (and I mean VERY). Most of what you hear in the film is an ondes martenot, and a sampled theremin played on a keyboard. 

The "lightning bolt" antennas you mentioned above were installed by Lev Termen's assistant and business partner, Julius Goldberg, on his RCA theremin in 1931. This particular RCA is now in the possession of yers trooly, ME! 

Here I am playing it with the TM in May of 2012.

http://www.youtube.com/watch?v=a2cQ7NYM_Wc

Well thank you for the nice compliment, Exlporer! I still use the TM quite often. It is fun to give the theremin a different sound. I do not have a great operatic voice, so to play the theremin with the TM somewhat satisfies the inner opera diva wannabe haha!

Explorer wrote: The Talking Machine also has a setting where the filters stay in the same place. There's a few videos (including the incomparable  Amethyste's) using the Talking Machine for a male tenor voice.

Thank you, Coalport.

I do love the Talking Machine sound, but it has the same problem as the theremin itself - too much of a good thing is too much. It is strictly for occasional use only. As a solo "effects" thereminist I find it beneficial to have a variety of effects to mix and match, so that my audience (and I) can enjoy a variety of sounds without suffering from ear fatigue.

In this piece from my forthcoming release Profluence & Occlusion (a double EP set) it is combined with a fuzz box (inserted into an effects loop that Thierry added to my etherwave - without that the hiss when the theremin is muted would be a lot louder - distortion really boosts the formant effect) a Flanger (I think - it was certainly a Marshall Regenerator, I believe it was in Flanger mode), a delay (as are the majority of things I do) and reverb. A faux stereo effect was added in post production. There is also a touch of Gig-FX Chopper around the 1:15 to give the "guh-guh" sound. 

Hopefully it is self-evident why I called it "Are You Here?"

https://soundcloud.com/beat-frequency/are-you-here

"Wow, nice paper Fred, thanks!  From the glory days of 4000 series CMOS, 741 op-amps, strong know-how, and some elbow grease" - Dewster

Yeah - things have changed!

< Start of rant agains the technical stupification of the masses >

IMO There was a time ( up to about the early '80s I guess) when most electronic "hobbyists" were really interested in electronics - all aspects, the theory, science and even the maths.. Many (most?) hobbyists were aspiring engineers.. And most popular magazines published articles to cater for this dominant group.

But the rot set in - "plug and play" - kits which gave little or no educational feedback - articles which pandered to the global stupification of the masses.. It became easy, and it became boring, and the whole electronic hobbyist market shrunk.. Simultaneously, the cost of ready-built items reduced to a level where it was far cheaper to buy ready-built than to buy the components for DIY.

Companies (like Maplin) who once catered for serious hobbyists, and sold components of which they stocked a large diverse range (some of the Maplin kits, like the ETI / Maplin 3600,4600,5600 synths were enormous projects) became marketing outlets for (mostly) rubbish - or at least for stuff you could buy in any high street.. Although still claiming to provide for electronics hobbyists, there are no kits they now do which couldnt be built by my 12 year old.

The "Chatterbox" article is typical of the quality one get from the pre-90's magazines - it goes into the theory in a depth hard to find (I have bought books and downloaded papers costing me a lot of money) at any price - the science, the electronics, the construction - all carefully and interestingly detailed.

I think that today the only magazines with any depth seem to be in the digital domain - in depth (sometimes) details about programming styles etc... But even this may be going back a few years (Byte etc).

With a few exceptions ( The wonderful articles by Douglas Self for example ) even "trade" journals have been grossly lacking on the analogue side - The majority of those starting electronics as a hobby have only "milk" available from hobby journals.. Yeah, sometimes there is "meat" - but its rare..

I was lucky - in my day it was tough going.. our hobby articles had more analogue depth than what those now leaving university with a degree have ever seen -

And I remember articles like the Chatterbox - and because of the digital revolution can usually find these and share them..

Fred

Coalport wrote,

Since the theremin is already an "effect" in the minds of most listeners, it would seem that the people who regularly use the Electro-Harmonix TM are adding an effect to an effect in hope that somehow they can turn the theremin into something other than what it is.....AN EFFECT!

I'm not saying that the theremin is an effect. I'm saying that most listeners think of its sound as an effect (and you gave many excellent examples in support of that). That's what some thereminists are trying to escape, that instant classification and dismissal.

To restate:

Since the sound of the theremin is already an "effect" in the minds of most listeners, the people who regularly use timbre-altering effects (like the talking Box and others) are using effects so they can escape the stereotypical theremin sound. 

Anyway, enough about this derailment. Anyone is free to start another topic about whether effects should be used usefully, if one feels strongly enough, instead of taking this conversation off-topic.

Now, back to formants!