I recorded sustained vowels and used IAIF (Iterative Adaptive Inverse Filtering) to extract my glottal waveform - the raw "buzz" before your throat shapes it into vowels.
What I expected: Rich, characterful human excitation to replace the mathematical model.
What I got: A softer, breathier sound than pure math! 😅
The mathematical LF model with sharpness cranked to 10 actually produces MORE harmonics than my actual voice does. That "chest resonant radio announcer" sound? That's aggressive glottal snap that not everyone has.



Borris
in reply to Tamas G • • •Tamas G
in reply to Borris • • •"ahh" sustained at normal pitch (~5 sec)
2. "ahh" sustained at low pitch (~5 sec)
3. "ahh" sustained at high pitch (~5 sec)
4. "shhh" sustained fricative (~5 sec)
5. "th" sustained unvoiced (~3 sec)
The "ahh" vowels are for glottal pulse extraction at different F0s. The "sh" and "th" are for noise/frication characteristics.
Recording tips:
• Condenser or dynamic mic (I used a Blue Snowball, AT2005 was too noisy)
• Peaks around -5 to -8 dB (NOT quiet - my first attempt at -30 dB was useless)
• Steady volume, no vibrato
• Quiet room
• 44100 Hz, mono
The key is getting a clean, loud, boring sustained vowel - no expression, just pure steady tone. The more monotone the better for extraction!
x0
in reply to Tamas G • • •Tamas G
in reply to x0 • • •1. We detect F0 (fundamental frequency) from the recording
2. Find individual glottal periods (pitch peak to pitch peak)
3. Resample each period to a common length
4. Average them together
So natural pitch drift is fine - the averaging smooths it out. Recorded at ~85 Hz but wobbled between 82-88? Doesn't matter, we're extracting the shape not the pitch.
x0
in reply to Tamas G • • •Tamas G
in reply to x0 • • •x0
in reply to Tamas G • • •Borris
in reply to Tamas G • • •x0
in reply to Borris • • •x0
in reply to x0 • • •Scott
in reply to x0 • • •x0
in reply to Scott • • •Tamas G
in reply to x0 • • •x0
in reply to Tamas G • • •x0
in reply to x0 • • •Tamas G
in reply to x0 • • •x0
in reply to Tamas G • • •Tamas G
in reply to x0 • • •Tamas G
in reply to x0 • • •x0
in reply to Tamas G • • •Tamas G
in reply to x0 • • •Borris
in reply to Tamas G • • •Tamas G
in reply to Tamas G • • •Martin
in reply to Tamas G • • •Borris
in reply to Martin • • •Andre Louis
in reply to Tamas G • • •Martin
in reply to Tamas G • • •Tamas G
in reply to Martin • • •Martin
in reply to Tamas G • • •Tamas G
in reply to Martin • • •Joshua
in reply to Tamas G • • •