Evaluation of a model of temporal weights in loudness judgments

Abstract

The onset of a sound receives a higher weight than later portions in time when its loudness is assessed, an effect commonly referred to as primacy effect. It is investigated if this effect can be predicted on the basis of an exponentially decaying function where the weight assigned to a temporal portion of a sound is the integral of this function over the segment duration. To test this model, temporal loudness weights were measured for sounds with different segment durations and total durations. The model successfully predicted essential aspects of the data.

Temporal weights in loudness: Investigation of the effects of background noise and sound level

“…In the present data, the estimated τ was about 240 ms for the conditions in background noise, whereas for the conditions in quiet, τ varied between 217 and 355 ms. Previous studies showed a dynamic range D r of about 4.70 for comparably long sound durations [10,11]. In the current study, a similar dynamic range ( D r = 5.05) was only found for condition Quiet SLquiet7.5 , whereas all other conditions showed higher dynamic ranges with D r between 10 and 27.48.…”

“…To quantify the magnitude and time course of the primacy effect, exponential decay functions were fitted to the mean weights at each of five conditions, as proposed in our previous work [10,11]. The weight assigned at the time t was assumed to be where t = 0 corresponds to the sound onset, c is the asymptotic weight at t → ∞ , D r is the weight at sound onset ( t = 0) relative to the asymptotic weight w ( ∞ ) = c (i.e., D r is the "dynamic range" of the weights), and the time constant τ quantifies the time needed for the weight to decay to a value of 1/ e of the weight range between w (0) and the asymptotic weight c .…”

“…To estimate temporal loudness weights, we used an established experimental paradigm from previous experiments (e.g., [7,10,11]). The target stimuli were level-fluctuating narrowband noises consisting of ten contiguous temporal segments.…”

“…Previous studies consistently show that the beginning of a time-varying sound is of higher importance for the perception of loudness than later temporal parts [7–9], which has been referred to as a primacy effect (for a review see [10]). The primacy effect can be described by an exponential decay function with a time-constant of about 200–300 ms [10,11]. The temporal weight at the beginning of the sound is 4 to 5 times higher than the asymptotic weight, and the weight assigned to a temporal portion of a sound is the integral of this function over the segment duration [11].…”

“…The primacy effect can be described by an exponential decay function with a time-constant of about 200–300 ms [10,11]. The temporal weight at the beginning of the sound is 4 to 5 times higher than the asymptotic weight, and the weight assigned to a temporal portion of a sound is the integral of this function over the segment duration [11]. In addition to the primacy effect, some studies also found higher perceptual weights assigned to the end of the sounds, commonly referred to as a recency effect [8,9].…”