©copyright Raimo Olavi Toivonen 1982-2021. All rights reserved. Last updated on  Jan 30, 2021.

Home  Signal displays 1985-  Multi-envelope displays 1998-  FFT displays 1985-  Cepstrum displays 1983-  Auditory displays 1983-  Loudness curves 1998-  Timbre spectrum 1983-  LPC displays 1992-  LTAS displays 1982-  Harmonic FFT displays 1989-  Waterfall displays 1983-  F0 displays 1983-  F0 histograms in semiscale 1989-  Jitter/shimmer 1990-  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

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ISA software


Auditory loudness spectra in Sone/Bark scale

Auditory loudness spectra have been in use on the Intelligent Speech Analyser ™ (ISA) since April 26, 1998.

Google Scholar "loudness scale"  1.760 results.

Google Scholar "sone scale"  805 results.

Google "loudness spectrum" Bark 521 results.

Google Scholar "loudness spectrum" Bark  151 results.

Google Images "loudness spectrum" "Bark"  many results.

Psychoacoustic links to "en.wikipedia.org/wiki":  Psychoacoustics   Auditory   Auditive   Auditory phonetics   Auditory system anatomy   Sone scale   Phon scale   Loudness   Equal-loudness contours   Fletcher-Munson curves   Bark scale   Critical bands   Auditory Filters   ERB scale (Equivalent rectangular bandwidth)   Mel scale   Semitone scale   Hertz scale   Sound pressure   SPL (Sound pressure level)   Stevens's power law   Stanley Smith Stevens   Harvey Fletcher   Karl Eberhard Zwicker

The terms "auditory" and "auditive" are different concepts. ISA expressly uses the term "auditory".

I am already 38 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 have coded as a DSP man 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 is 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).

I have used the above Bark conversion formulas since 1983.



SYNTE2 said 42 years ago 1977, "Tämä on ohjelma, joka käsittelee tulevaisuutta" (This is a program about the future). The loudness values ​​for the named segments on the sone scale are "Tämä" 31, 48, 33, 46, "on" 53, 32, "ohjelma" 46, 28, 40, 55, 56, 34, 49, "joka" 34, 54, 20, 58, "käsittelee" 44, 62, 60, 55, 16, 56, 61, 57, "tulevaisuutta" 20, 44, 47, 52, 27, 57, 54, 60, 13, 62.

Loudness spectrum in sone scale. In the case of the image, the total loudness in scale 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" 1983-86 at Acoustics Laboratory May 1987. 110 pages. ISBN 951-754-154-6.