İcopyright Raimo Olavi Toivonen 1985-2021. All rights reserved. Last updated on Jan 30, 2021.

Home  Signal displays 1985-  Multi-envelope displays 1998-  FFT displays 1985-  Cepstrum displays 1983-   LPC displays 1992-  Auditory displays 1983-   Loudness displays 1995-   Loudness curves 1998-  Timbre spectrum 1983-   LTAS displays 1982-  Harmonic FFT displays 1989-  Waterfall displays 1983-  F0 displays 1983-  Jitter/shimmer 1990-  Computer Voice Fields in Hz scale 1983-  FFT spectrogram displays 1985-  LPC spectrogram displays 1998-  Auditory spectrogram displays 1985-  Formant charts in Bark, ERB, mel, semitone and Hz scales 1988-   Synte 2 demo video speech on 8.8.1977 analyzed 2018-  Formant charts of world languages in Bark scale 2018-   Other links

Works   Works before ISA


ISA software

F0 histograms in lin/st scale

My fast F0 analysis is done by bandpass filtering the time signal and then searching every voice period in the time signal using my unique method. By searching in the time signal, each voice period can be determined with high accuracy F0, and even small variations in the fundamental frequency can be seen.

My unique F0 algorithm also makes it possible to determine the jitter and the shimmer.

My F0 algorithm has been in use for 37 years since 1984 and has been running in real time on the NEC's µPD7720 signal processor since 1985, 36 years ago.

Analysis pictures I have coded from the very beginning in Neon object-oriented programming language.

Who else would have done pitch analysis in Finland already on 1984, 37 years ago, and already on 1985 in real time?

My F0 analysis I have coded as a DSP man totally from zero to machine languages.

Hz is converted to st by the formula x/st=57+12log2(f/440) ja
St is converted to Hz by the formula f/Hz=440(2(x-57)/12).

F0 histogram display in semi-scale

F0 distribution on a semitone scale.

F0 histogram display in semi-scale

F0 distributionw on a semitone scale.

F0 distribution on a semitone scale.

F0 distribution on a tenth semitone scale.