title: Forward masking of dynamic acoustic intensity: effects of intensity region and end-level.
abstract: Overestimation of loudness change typically occurs in response to up-ramp auditory stimuli (increasing intensity) relative to down-ramps (decreasing intensity) matched on frequency, duration, and end-level. In the experiment reported, forward masking is used to investigate a sensory component of up-ramp overestimation: persistence of excitation after stimulus presentation. White-noise and synthetic vowel 3.6 s up-ramp and down-ramp maskers were presented over two regions of intensity change (40-60 dB SPL, 60-80 dB SPL). Three participants detected 10 ms 1.5 kHz pure tone signals presented at masker-offset to signal-offset delays of 10, 20, 30, 50, 90, 170 ms. Masking magnitude was significantly greater in response to up-ramps compared with down-ramps for masker-signal delays up to and including 50 ms. When controlling for an end-level recency bias (40-60 dB SPL up-ramp vs 80-60 dB SPL down-ramp), the difference in masking magnitude between up-ramps and down-ramps was not significant at each masker-signal delay. Greater sensory persistence in response to up-ramps is argued to have minimal effect on perceptual overestimation of loudness change when response biases are controlled. An explanation based on sensory adaptation is discussed.
authors.affiliation: MARCS Institute, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751, Australia. k.olsen@uws.edu.au
authors.forename: Kirk N
authors.initials: KN
authors.lastname: Olsen
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Stevens
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D008144:Loudness Perception; D008297:Male; D010470:Perceptual Masking; D010898:Pitch Perception; D011571:Psychoacoustics; D013018:Sound Spectrography; D013067:Speech Perception