|©copyright Raimo Olavi Toivonen 1985-2021. All rights reserved. Last updated on Jan 30, 2021.|
Signal displays 1985-
Multi-envelope displays 1998- FFT displays 1985-
Cepstrum displays 1983-
displays 1995- Loudness curves 1998-
LTAS displays 1982-
Harmonic FFT displays 1989-
Waterfall displays 1983- F0 displays 1983-
F0 histograms in semitone scale 1989-
Computer Voice Fields 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
The calculation uses the PARCOR method.
Over the years, I have coded as a DSP man
PARCOR-laskennan of the Intelligent Speech Analyser™ (ISA) program
(1) for the Texas 16-bit TMS320 signal processor family in machine language,
(2) for Motorola's 16 and 32-bit M68000 microprocessor families in machine language and C language,
(3) for IBM 600 Series 32-bit PowerPC Microprocessor Family in machine language and C language,
(4) for Intel 32-bit and 64-bit microprocessor families in C++ language.
The windowing of the signal is by a Hamming window, a rectangular window or a Blackman-Harris window of more than 90 dB.
Formants search is performed in a unique way by first filtering the LPC spectral curve by bandpass filtering and then searching the sharpened spectrum for peaks by a unique method.
Analysis pictures I have coded from the very beginning in Neon object-oriented programming language.
converted to Bark by the formula x/Bark=7ln[f/650+√(1+(f/650)2)]
and Barks are converted to Hz by the formula f/Hz=650sinh(x/7).
Hz is converted to ERBs by the formula x/ERB=21,3log10(1+f/228,7) and ERBs are converted to Hz by the formula f/Hz=228,7(10x/21,3-1).
Hz is converted to mel by the formula x/mel=2595log10(1+f/700) and mels are converted to Hz by the formula f/Hz=700(10x/2595-1).
FTT and LPC spectrum of the vowel a:
FTT and LPC spectrum of the vowel e:
FTT and LPC spectrum of the vowel i:
FTT and LPC spectrum of the vowel o:
FTT and LPC spectrum of the vowel u:
FTT and LPC spectrum of the vowel y:
FTT and LPC spectrum of the vowel ä:
FTT and LPC spectrum of the vowel ö: