title: The dynamic range paradox: a central auditory model of intensity change detection.
abstract: In this paper we use empirical loudness modeling to explore a perceptual sub-category of the dynamic range problem of auditory neuroscience. Humans are able to reliably report perceived intensity (loudness), and discriminate fine intensity differences, over a very large dynamic range. It is usually assumed that loudness and intensity change detection operate upon the same neural signal, and that intensity change detection may be predicted from loudness data and vice versa. However, while loudness grows as intensity is increased, improvement in intensity discrimination performance does not follow the same trend and so dynamic range estimations of the underlying neural signal from loudness data contradict estimations based on intensity just-noticeable difference (JND) data. In order to account for this apparent paradox we draw on recent advances in auditory neuroscience. We test the hypothesis that a central model, featuring central adaptation to the mean loudness level and operating on the detection of maximum central-loudness rate of change, can account for the paradoxical data. We use numerical optimization to find adaptation parameters that fit data for continuous-pedestal intensity change detection over a wide dynamic range. The optimized model is tested on a selection of equivalent pseudo-continuous intensity change detection data. We also report a supplementary experiment which confirms the modeling assumption that the detection process may be modeled as rate-of-change. Data are obtained from a listening test (N = 10) using linearly ramped increment-decrement envelopes applied to pseudo-continuous noise with an overall level of 33 dB SPL. Increments with half-ramp durations between 5 and 50,000 ms are used. The intensity JND is shown to increase towards long duration ramps (p<10(-6)). From the modeling, the following central adaptation parameters are derived; central dynamic range of 0.215 sones, 95% central normalization, and a central loudness JND constant of 5.5×10(-5) sones per ms. Through our findings, we argue that loudness reflects peripheral neural coding, and the intensity JND reflects central neural coding.
authors.affiliation: Centre for Digital Music, Queen Mary University of London, London, United Kingdom. andy.simpson@eecs.qmul.ac.uk
authors.forename: Andrew J R
authors.initials: AJ
authors.lastname: Simpson
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Reiss
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D003198:Computer Simulation; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008144:Loudness Perception / Q000502:physiology*; D008954:Models, Biological; D013016:Sound
references.citation: Nat Neurosci. 2005 Dec;8(12):1684-9
references.pmid: 16286934
references.citation: J Acoust Soc Am. 1990 Jun;87(6):2643-54
references.pmid: 2373799
references.citation: J Acoust Soc Am. 1997 Sep;102(3):1779-90
references.pmid: 9301055
references.citation: J Acoust Soc Am. 1988 Jul;84(1):172-8
references.pmid: 3411045
references.citation: J Acoust Soc Am. 1997 Nov;102(5 Pt 1):2906-19
references.pmid: 9373977
references.citation: Hear Res. 2009 Jul;253(1-2):107-15
references.pmid: 19345257
references.citation: J Acoust Soc Am. 1974 Dec;56(6):1835-47
references.pmid: 4443483
references.citation: Proc Natl Acad Sci U S A. 1922 Jan;8(1):5-6.2
references.pmid: 16586849
references.citation: J Acoust Soc Am. 1997 Nov;102(5 Pt 1):2892-905
references.pmid: 9373976
references.citation: J Neurosci. 2008 Jun 18;28(25):6430-8
references.pmid: 18562614
references.citation: J Acoust Soc Am. 1999 Oct;106(4 Pt 1):1917-24
references.pmid: 10530016
references.citation: Science. 1983 Sep 16;221(4616):1206-8
references.pmid: 6612337
references.citation: Exp Brain Res. 1980;40(1):115-8
references.pmid: 7418755
references.citation: J Acoust Soc Am. 2007 Mar;121(3):1632-41
references.pmid: 17407900
references.citation: J Acoust Soc Am. 1968 Aug;44(2):576-81
references.pmid: 5665529
references.citation: Neuron. 2011 Jun 23;70(6):1178-91
references.pmid: 21689603
references.citation: J Acoust Soc Am. 1990 Mar;87(3):1255-65
references.pmid: 2324392
references.citation: J Neurosci. 2009 Nov 4;29(44):13797-808
references.pmid: 19889991
references.citation: J Acoust Soc Am. 1971 Feb;49(2):Suppl 2:467+
references.pmid: 5541744
references.citation: J Acoust Soc Am. 1969 Aug;46(2):372-83
references.pmid: 5804107
references.citation: J Acoust Soc Am. 2006 Jun;119(6):3950-9
references.pmid: 16838538
references.citation: J Acoust Soc Am. 2001 May;109(5 Pt 1):2098-102
references.pmid: 11386561
references.citation: Hear Res. 2001 May;155(1-2):41-53
references.pmid: 11335075
references.citation: J Acoust Soc Am. 2006 Jun;119(6):3919-30
references.pmid: 16838535
references.citation: Neuron. 2010 May 27;66(4):610-8
references.pmid: 20510864