|©copyright Raimo Olavi Toivonen 1982−2019. All rights reserved. Last updated on September 15, 2019.|
Home Signal displays 1985−
Multi-envelope displays 1998− FFT displays 1985− Cepstrum displays 1983−
Auditory displays 1983−
Loudness displays 1995−
Timbre spectrum 1983− LPC displays 1992− LTAS displays 1982−
Harmonic FFT displays 1989−
Waterfall displays 1983− F0 displays 1983− F0 histograms with 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− Bark scale 1983− ERB scale 1996− Semitone scale 1989−
Sone scale 1995− Formant charts of world
languages in Bark scale 2018−
Google Scholar "loudness curves" "Bark" 256 results.
Google Images "loudness curves" "Bark" many results.
Auditory system anatomy
ERB scale (Equivalent rectangular bandwidth)
SPL (Sound pressure level)
Stevens's power law
Stanley Smith Stevens
Karl Eberhard Zwicker
The terms "auditory" and "auditive" are different concepts. ISA expressly uses the term "auditory".
I am already 36 years used routinely Bark scale and the auritory filter bank model since my Otaniemi year 1983. I developed our own auditory filter bank model together with professor Matti Karjalainen.
Over the years, I
auditory filter bank model completely from zero
(1) for "PDP-11/34 Floating Point Systems FPS 100 Vector Processor" in Fortran,
(2) for the Texas 16-bit TMS320 signal processor family in machine language,
(3) for Motorola's 16 and 32-bit M68000 microprocessor families in machine language and C language,
(4) for IBM 600 Series 32-bit PowerPC Microprocessor Family in machine language and C language,
(5) for Intel 32-bit and 64-bit microprocessor families in C++ language.
Analysis pictures I have coded from the very beginning in Neon object-oriented programming language.
Loudness formula is N=2(L-40)/10. Unit of loudness is Sone. L is sound volume level dBSPL of sine sound.
Hz values are converted to Bark values by the formula Hz->Bark=7asinh(f/650)=7ln(f/650+√(1+(f/650)2)) and Bark values are converted to Hz values by the formula Bark->Hz=650sinh(x/7).
I have used the above Bark conversion formulas since 1983.
Loudness spectrum in sone scale. In the case of the image, the total loudness in sones is almost entirely generated by speech below 1.5 kHz.
The man says 8 long vowels. When segmented and raised by the ISA's segment editor to the same SPL level, the sone scale yields values of 47, 44, 33, 42, 35, 34, 40, 36. Vocals of the same volume differ markedly in the sone scale of 33–47.
The woman says 8 long vowels. When
segmented and raised by the ISA's segment editor to the same SPL level, the sone
scale yields values of 53, 46, 36, 44, 34, 34, 54, 36. Vocals of the same
loudness differ significantly from one another to a sone scale of 34–54.
The SPL curve and loudness curve overlap with the test phrase "ai ai kun on kaunis päivä" (ai ai when it's a beautiful day).
Final Report of the basic 4 years research project "Auditory modelling of speech perception" 1983–1986 at Acoustics Laboratory May 1987. 110 pages. ISBN 951-754-154-6.