problema fizica - sunet - Page 2

#19
mdionis

Posted 24 March 2014 - 15:56

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quantico2708, on 24 martie 2014 - 14:54, said:

pe scurt : Omul percepe 30dB ca fiind de 2 ori mai zgomots decat 20dB ?

Cu o buna aproximatie, daca sunetul are frecventa in zona 1 kHz. Perceptia intensitatii sunetelor e ceva mai complicata, poti gasi de exemplu aici niste informatii generice, insa sfatul meu e sa nu iti bati capul cu acest capitol din acustica legat de fiziologie daca nu este neaparat necesar.

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#20
eugeniusro

Posted 24 March 2014 - 20:05

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parerea mea este ca omul percepe de doua ori mai zgomotos 23 dB decat 20 dB dar daca tu il crezi pe mdionis e problema ta, in realitate tocmai perceperea logaritmica a puterii sonore este dictata de curba de raspuns a urechii umane.

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#21
mdionis

Posted 24 March 2014 - 21:44

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eugeniusro, on 24 martie 2014 - 20:05, said:

parerea mea este ca omul percepe de doua ori mai zgomotos 23 dB decat 20 dB dar daca tu il crezi pe mdionis e problema ta, in realitate tocmai perceperea logaritmica a puterii sonore este dictata de curba de raspuns a urechii umane.

E frumos sa iti expui pareri in public dar e si mai frumos sa le sustii cu altceva decat cu "I say so":

The phon is a unit of physical loudness level that is referenced to a sound-pressure level at 1 kHz. This is useful, but it tells us little about human reaction to loudness of sound. Some sort of subjective unit of loudness is needed. Many experiments conducted with hundreds of subjects and many types of sound have yielded a consensus that for a 10-dB increase in sound-pressure level, the average person reports that loudness is doubled. For a 10-dB decrease in sound level, subjective loudness is cut in half. (Alton, Everest, Pohlmann - Master Handbook of Acoustics, 5th ed., McGraw-Hill 2009)

On the basis of results from these two methods, Stevens suggested that loudness, L, was a power function of physical intensity, I : L = kI^0.3x , (13.3)
where k is a constant depending on the subject and the units used. In other words, the loudness of a given sound is proportional to its intensity raised to the power 0.3. Note that this implies that loudness is not linearly related
to intensity; rather, it is a compressive function of intensity. An approximation to this equation is that the loudness doubles when the intensity is increased by a factor of 10, or, equivalently, when the level is increased by 10 dB. In practice, this relationship only holds for sound levels above about 40 dB SPL. For lower levels than this, the loudness changes with intensity more rapidly than predicted by the power-law equation. (Rossing - ed., Springer Handbook of Acoustics, Springer 2007)

Daca nu stii bine despre ce vorbesti, e indicat sa fii mai prudent in afirmatii.

Edited by mdionis, 24 March 2014 - 21:45.

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#22
Handicarpati

Posted 25 March 2014 - 06:57

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eugeniusro, on 24 martie 2014 - 20:05, said:

parerea mea este ca omul percepe de doua ori mai zgomotos 23 dB decat 20 dB dar daca tu il crezi pe mdionis e problema ta, in realitate tocmai perceperea logaritmica a puterii sonore este dictata de curba de raspuns a urechii umane.

deschide winamp porneste egalizatoru si mareste cu 3 decibeli o sa auzi pe urechea ta

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problema fizica - sunet

#19 mdionis Posted 24 March 2014 - 15:56

#20 eugeniusro Posted 24 March 2014 - 20:05

#21 mdionis Posted 24 March 2014 - 21:44

#22 Handicarpati Posted 25 March 2014 - 06:57

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#19
mdionis

Posted 24 March 2014 - 15:56

#20
eugeniusro

Posted 24 March 2014 - 20:05

#21
mdionis

Posted 24 March 2014 - 21:44

#22
Handicarpati

Posted 25 March 2014 - 06:57