Sweep-induced acceleration in loudness change and the “bias for rising intensities”

Abstract

A pure tone changing continuously in intensity shows sweep-induced fading (SIF) of loudness as intensity sweeps down and may show a lesser degree of sweep-induced enhancement (SIE) as intensity sweeps up (Canévet & Scharf, 1990); the former effect has been called decruitment, the latter upcruitment. An opposite effect-upsweeps being judged to show more loudness change than downsweeps-has been reported by Neuhoff (1998). These disparate results might stem from several procedural differences. We found that differences in the sweep's duration and intensity level did not account for the disparity, nor did the presence of a steady tone preceding the sweep. In a second experiment, direct judgments of sweep size, such as those Neuhoff's (1998) listeners made, were affected not only by sweep size itself, but also by the intensity at the end of the sweep. The latter effect was especially marked for upsweeps. Neuhoff's (1998) proposed "bias for rising intensities" was found only with a method for judging sweep size that is more sensitive to end level than to sweep size.

End level bias on direct loudness ratings of increasing sounds

“…In these studies direct ratings were used, i.e., the loudness change reported was a single judgment. The overestimation for upramps has been found to be strongly dependent on end level of the ramp rather than on ramp size (Teghtsoonian et al, 2005). On the other hand, no loudness change overestimation for upramp sounds was found (Canévet et al, 2003;Susini et al, 2007), but a strong effect of ramp size was observed-as it could have been expected when measuring loudness change (Canévet et al, 2003).…”

“…The synthetic vowel sound was based on Klatt's (1980) algorithm with a fundamental frequency of 100 Hz and three formant frequencies (450, 1450 and 2450 Hz) as in Neuhoff's (1998) study. In order to compare our results with those from previous studies (Neuhoff, 1998;Teghtsoonian et al, 2005), similar configurations of the control parameters were chosen.…”

“…Teghtsoonian et al (2005) showed that when an estimation of the start level is asked just after the end of the sound, the loudness is overestimated compared to the loudness of a 10-s plateau played prior to the beginning of an upramp. Then, in this experiment, the loudness estimation of the start level was extracted from the loudness function obtained for the third group during the primarily experiment.…”

“…A significant number of studies have recently investigated the loudness of sounds that increase and decrease continuously in level (Neuhoff, 1998(Neuhoff, , 2001Canévet et al, 2003;Teghtsoonian et al, 2005;Susini et al, 2007;Olsen et al, 2010;Olsen and Stevens, 2010). This question is important for the study of moving sources for example, as intensity change is the dominant motion cue for mediating the effects of approaching sound sources (Bach et al, 2009).…”

“…Results are different among the studies. On the one hand, an overestimation of loudness change for upramp sounds was revealed (Neuhoff, 1998(Neuhoff, , 2001Teghtsoonian et al, 2005), explained by Neuhoff (1998Neuhoff ( , 2001) as a survival advantage for detecting an approaching sound source. In these studies direct ratings were used, i.e., the loudness change reported was a single judgment.…”