Subject: specific loudness calculation: ambiguity of excitation From: "Rossi Mark (PA-ATMO/EES21) *" <Mark.Rossi(at)DE.BOSCH.COM> Date: Thu, 8 Jul 2004 17:11:18 +0200Dear list, I spent 2 days now searching for the answer to my question, reading tens of papers and articles, asking lots of people... I hope you're not offended by the triviality of it. The specific loudness as defined by Zwicker & Fastl in [1] (page 224; equation 8.5) reads N'(z) = N'_0 *((E_{TQ}(z))/s(z)*E_0))^{0.23} * [(1-s(z)+s(z)*E(z)/E_{TQ}(z))^{0.23} -1] sone/Bark I found N'_0 and s(z) in [1] and an equation to calculate the threshold in quiet E_{TQ} in [2]. But it seems impossible to me to figure out, what the excitations E(z) and E_0 exactly are. In [1] you can read: "...and E_0 is the excitation that corresponds to the reference intensity I_0 = 10^{-12} W/m^2." ? The questions are (given I already calculated the excitation pattern): - when E_0 is the _intensity_ ratio between the measured intensity at a critical band rate I_M and I_0 ( E_0 = I_M/I_0 ): what is E(z) supposed to be? and should the threshold in quiet in the first parenthesis be given as intensity (10^L) too, in order to keep the term nondimensional? - if the first assumption is correct: is E(z) the excitation _level_ at the considered critical band rate? - when E(z) = E_0: why they used different expressions? The mentioned chapter in [1] leaves this completely open and me in frustration. I hope someone here can help me with my 'simple' question. Thanks and regards, Mark Rossi [1] E.Zwicker, H.Fastl: "Psychoacoustics" 2nd updated edition Springer, 1999 [2] E.Terhardt: "Calculating Virtual Pitch", Hearing Research, vol. 1, p. 155-182 1979 -- Mark Rossi Robert Bosch GmbH PA-ATMO/EES21 Postfach 30 02 20 70442 Stuttgart Tel: (0711) 811-2 34 77 Fax: (0711) 811-4 43 66 Besucheranschrift/Visitors: Robert Bosch GmbH PA-ATMO/EES21 Bau 203/2 Wernerstraße 51 70469 Stuttgart-Feuerbach