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

Abstract

Previous research has consistently shown that for sounds varying in intensity over time, the beginning of the sound is of higher importance for the perception of loudness than later parts (primacy effect). However, in all previous studies, the target sounds were presented in quiet, and at a fixed average sound level. In the present study, temporal loudness weights for a time-varying narrowband noise were investigated in the presence of a continuous bandpass-filtered background noise and the average sound levels of the target stimuli were varied across a range of 60 dB. Pronounced primacy effects were observed in all conditions and there were no significant differences between the temporal weights observed in the conditions in quiet and in background noise. Within the conditions in background noise, there was a significant effect of the sound level on the pattern of weights, which was mainly caused by a slight trend for increased weights at the end of the sounds (“recency effect”) in the condition with lower average level. No such effect was observed for the in-quiet conditions. Taken together, the observed primacy effect is largely independent of masking as well as of sound level. Compatible with this conclusion, the observed primacy effects in quiet and in background noise can be well described by an exponential decay function using parameters based on previous studies. Simulations using a model for the partial loudness of time-varying sounds in background noise showed that the model does not predict the observed temporal loudness weights.

Temporal Loudness Weights Are Frequency Specific

“…For all conditions in both experiments, primacy effects at the onset of the sounds were observed, in the sense that the first segments of a sound received higher weights compared to the following segments. This is compatible with previous data (e.g., Pedersen and Ellermeier, 2008 ; Rennies and Verhey, 2009 ; Fischenich et al, 2019 ).…”

“…It is also compatible with neurophysiological data showing entrainment to channel-specific instantaneous loudness in cortical MEG components up to about 100 ms (Thwaites et al, 2017). One should keep in mind, however, that the attack-decay type of temporal integration assumed by the TVL-model does not predict a primacy effect, as demonstrated by simulation results in Fischenich et al (2019).…”

“…In loudness judgments of time-varying sounds, higher perceptual weights are assigned to the first few hundred milliseconds of a sound compared to later temporal portions (e.g., Namba et al, 1976 ; Ellermeier and Schrödl, 2000 ; Plank, 2005 ; Pedersen and Ellermeier, 2008 ; Dittrich and Oberfeld, 2009 ; Rennies and Verhey, 2009 ; Ponsot et al, 2013 ). This primacy effect can be described by an exponential decay function with a time constant of about 300 ms ( Hots et al, 2018 ; Oberfeld et al, 2018 ; Fischenich et al, 2019 ). The temporal weighting was reported to be largely independent of the spectral weighting ( Oberfeld et al, 2012 ).…”

“…In most previous experiments on temporal loudness weights, a broadband noise ( Pedersen and Ellermeier, 2008 ; Dittrich and Oberfeld, 2009 ; Oberfeld et al, 2018 ), a single narrowband noise band ( Rennies and Verhey, 2009 ; Fischenich et al, 2019 ) or a pure tone ( Ponsot et al, 2013 ) was presented. The corresponding data thus do not provide an answer to the question of whether the temporal weights are assigned on a frequency-specific basis.…”

“…Studies on temporal loudness weights ( Oberfeld and Plank, 2011 ; Oberfeld, 2015 ; Fischenich et al, 2019 ) discussed the possibility that the temporal weighting pattern observed for loudness judgments of time varying sounds is caused by the response characteristics of auditory nerve (AN) fibers. AN fibers show an initial peak in their firing rate at the onset of a sound ( Kiang et al, 1965 ).…”