FS1R Formant Shaping, Part 2: Human formants and terms

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What is a formant anyway?

To truly understand the FS1R, you need some background information, and you need to understand some of the terminology.

Let's follow the journey that air makes when you speak.
  • When you speak, you blow air out of your lungs. 
  • When you close your vocal cords a bit, the air makes causes vibrations. 

    • The more you open the folds:
      • the more distance they need to cross to open/close
      • the longer it takes to flap back and forth
      • the lower the frequency that the chords will flap
      • the lower the tone it produces
      • for humans, this flapping happens about 100 to 300 times per second (100-300Hz)
      • Yamaha calls this the Fundamental Frequency

    • This rhythmic oscillation produces a somewhat boring "buzzing" kind of sound.
      • The buzz consists of short bursts of sound that are rich with overtones.
      • Each burst fades out when the vocal folds close

  • On the way out, the air passes your throat, tongue, checks, lips, nose and teeth. 
    • By moving those strategically, you can force the airflow to cause specific resonances. 

    • Voiced example: 
      • When you tighten the space between your tongue and the top of your mouth, or tighten your lips, air will have less space to flow.

        Eventually, the turbulence will cause certain frequencies to become louder.

        That         phenomenon, of a specific frequency that starts resonating, is a formant.
        • The frequency where it occurs is the Formant Frequency.
        • The amount that it resonates is called Formant Level by Yamaha.
        • It produces a tone-like resonance. This is a Voiced Formant.
        • If you close your lips, you'll get some resonances. Close it more, and the frequency of the resonance will go up. This can even go as far as causing a whistle.
    • Unvoiced example: 
      • When you force air to flow between your teeth, there's a lot of bouncing and turbulence. 
        • Think of letters like S, F, or P
        • It won't result in one prominent resonant frequency.
        • It starts sounding like noise, with a certain peak frequency though.
        • This is called an Unvoiced Formant

So, this is how we humans produce speech and formants. 


Next time, let's see how the FS1R manages to produce similar sounds, without having a physical throat or teeth.

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