Loudness Adaptation with Modulated Stimuli

Abstract

At lows ensation levels, loudness adaptation is described as ad ecrease in loudness judgment overt ime of a steady,fixed-intensity auditory stimulus, presented monaurally.Similarly,athigh sensation levels, loudness enhancement is described as an increase in loudness judgment overtime. In the present study,loudness adaptation and loudness enhancement were measured for unmodulated sinusoids, sinusoidally amplitude-modulated sinusoids, and mixed-modulated sinusoids. Each stimulus had acarrier frequencyof500 or 2000 Hz, waspresented at 30 or 70 dB SL (sensation level),a nd had ad uration of 302 s. The modulation frequencyw as 40 Hz. Loudness adaptation percentages were measured using as uccessive magnitude estimation task. At 70 dB SL, small amounts of loudness enhancement were found at 500 Hz, and no loudness enhancement wasfound at 2000 Hz, for all modulation types. At 30 dB SL, loudness adaptation wasfound for all modulation types with more adaptation at 2000 Hz than at 500 Hz. Adifference in loudness adaptation wasfound between modulation types, with am ore pronounced difference at 500 Hz. Mixed-modulated sinusoids showed more adaptation than unmodulated sinusoids, which in turn showed more adaptation than sinusoidally amplitude-modulated sinusoids. The sinusoidally amplitude-modulated stimulus condition did no longer showl oudness adaptation at 30 dB SL and 500 Hz. In addition, if loudness adaptation occurred, moderate buts ignificant correlations were found between the participants' absolute thresholds in dB SPLand their loudness adaptation percentages at 30 dB SL.

Objective Binaural Loudness Balancing Based on 40-Hz Auditory Steady-State Responses. Part I: Normal Hearing

“…Behavioral loudness balancing was done for at least one fixed level in the left ear. Although other studies were interested in maturational or developmental differences (e.g., Poelmans, Luts, Vandermosten, Ghesquière, & Wouters, 2012 ; Vanvooren, Hofmann, Poelmans, Ghesquière, & Wouters, 2015 ), in this study, typical patterns were investigated for a population of young, NH individuals to assess the feasibility of using 40-Hz ASSR amplitudes for binaural loudness balancing.…”

“…For the EEG recordings, the stimulus duration was 307.2 s, which was necessary to reduce the EEG recording noise, as the noise is random and can be averaged out, while the response remains stable. Since low stimulus levels that could lead to behavioral loudness adaptation ( Van Eeckhoutte, Wouters, & Francart, 2015 ) were not used, and we did not expect adaptation of the 40-Hz ASSR amplitudes ( Van Eeckhoutte, Luke, Wouters, & Francart, 2018 ), the stimulus duration probably did not affect the results.…”

Preface

“…They found that loudness is the main factor used by participants to judge the similarity between sounds. Despite this importance of loudness in auditory perception of sounds, the temporal aspects described in [2,3,4,5] are still not included in current loudness models. This may be part of the reason whyd ynamic models are not always predicting loudness of time-varying sounds as shown in [7] and [8].…”

“…The effect of amplitude modulation on loudness perception is also the topic of vanE eckhoutte et al [2], the first paper of the special section. In contrast to the early study by Bauch, the influence of amplitude modulation on loudness adaptation is investigated.…”

“…It is shown that this change in perceivedloudness overtime is different for modulated and unmodulated sounds and is affected by the type of modulation. While Eeckhoutte and colleagues [2] used signals with no overall change in intensity overtime, Ponsot et al [3] and Olsen and Herff [4] investigated the loudness for stimuli with rising or falling intensity.S everal previous studies showed that rising sounds are often louder and perceivedaschanging more in loudness than falling sounds although their long-term spectra are the same. Ponsot and colleagues [3] investigated the role of frequencycontent and levelonthis direction-specifice ff ect in global loudness.…”