Continuous judgment of level-fluctuating sounds and the relationship between overall loudness and instantaneous loudness

Understanding how vibration affects discomfort is an important factor for improving work and travelling experience. Methods of evaluating health effects from whole-body vibration are closely linked to those for evaluating discomfort in ISO 2631-1. The standard includes a method to evaluate discomfort using twelve axes of vibration with a similar approach to that for evaluating health effects; thus using all twelve axes gives a possibility to evaluate both health and discomfort. The full 12-axis method has not been widely used in practice or validated in a multi-axis environment. The standard guidance is not explicit, thus different interpretations are possible especially when determining the method of comparing or combining vibration in different axes. Furthermore there are not enough studies conducted in multi-axis environments to suggest the optimal combination of axes. In this study ISO 2631-1 method was tested and optimised using a multi-axis test bench at Loughborough University, UK. Subjects were exposed to stimuli which represented vibration characteristics from field measurements. Each stimulus, lasting 15 s, was judged using a continuous judgement, cross-modal matching method. The seat translational and rotational and the backrest translational axes were used in the analyses. There was no vibration at the floor, in order to constrain the number of independent variables. Results showed that correlation for discomfort improved with more complex analysis procedures. However a good correlation was also achieved using just seat translational axes with optimised multiplying factors. The results showed that frequency weightings and r.m.s. averaging improved correlation between vibration and subjective ratings of discomfort. Multiplying factors specified in ISO 2631-1 degraded the correlation between objective and subjective measures of discomfort, therefore an improved set of factors were determined. The new factors showed improvement by placing more emphasis on seat fore-and-aft and lateral axes.

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“…Subjects evaluated discomfort of each stimulus using the continuous judgement method 26) . Subjects were presented a discomfort line (Fig.…”

Section: Subject Judgementmentioning

confidence: 99%

Relative Contribution of Translational and Rotational Vibration to Discomfort

Marjanen

Mansfield

2010

Ind Health

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“…Being able to estimate the exposure associated to an urban walking trip has many potential interests, such as for informing pedestrians about the potential restorative capacity or even health benefit of their intended walk. To date, only few studies are available that investigated how outdoor soundscapes are assessed over time [33]- [35], and these studies show that recency or presentation-order effects can be observed during transitions between different sound environments [36]. Likewise, only few studies investigated the temporal dynamics of sound environments and their assessment [33].…”

Section: Introductionmentioning

confidence: 99%

Modeling Soundscape Pleasantness Using perceptual Assessments and Acoustic Measurements Along Paths in Urban Context

Aumond¹,

Can²,

Coensel³

et al. 2017

Acta Acustica united with Acustica

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Mapping the pleasantness of an urban environment is an alternative approach, closer to the city dweller's perception, than standardized sound levels cartography. This study reports on modeling pleasantness in urban context using perceptual assessments and sound measurements for specific locations during an urban walk. These assessments have been collected from four groups of approximately ten participants on 19 different assessment locations, along a 2,1 km-long path traveled in both directions. Simultaneously, ⅓ octave band sound levels and audio were recorded. Perceptual and physical models of pleasantness are proposed for specific locations based on multiple linear regressions. A multilevel analysis was performed, and it is shown that a perceptual model that includes perceived loudness joined to the perceived time of presence of traffic, voices and birds explains 90% of the pleasantness variance due to the sound environment variations. Physical models that include the original acoustic indicators that are most correlated with perceptual variables explain 85% of this variance. Thanks to these models, a unique averaged pleasantness value is defined for each assessment location from the perceptual or physical collected assessments. The Pearson's correlation coefficient between the averaged perceived pleasantness and the modeled values from perceptual assessment reaches r(19)=0.98, and r(19)=0.97, with the modeled values from physical measurements. These results make it possible to consider the use of this kind of models in a cartographic context. As the path was traveled in both directions, the presentation-order effect has also been assessed, and it has been found that path direction did not have a significant impact on the pleasantness assessment at specific locations, except when very strong sound environment changes occurred. Finally, the study gives some insights about the retrospective global pleasantness assessment for urban walks. For very short walks between two assessment locations, a recency effect is shown. Nevertheless, this effect doesn't seem to be significant when longer routes are assessed.

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“…Although the howling perception, accessed by a specific onomatopoeic description, might be evoked between 250-500 ms, a non-howling aspect is discovered. The duration upper limit for the constant factor could be 2.5 s, the psychological present, which according to [25] plays a major role in the overall loudness judgment of sounds fluctuating in level. The specific loudness of a tone within a noise masker characterized by a high S/N ratio can be described by a linear relationship between log-loudness and tone level (cf.…”

Section: Resultsmentioning

confidence: 99%

“…This is related to the question how the instantaneous pitch salience is related to the overall judgment of tonal content. More specifically, Kuwano and Namba [25] found in the case of loudness a 2.5 s time constant, which relates to the psychological present. In this way, all tone lengths used in this present experiment can be regarded as ''within the present,'' i.e.…”

Section: Howling Ratio Scale Constructionmentioning

confidence: 88%

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The influence of tone length and S/N-ratio on the perception of tonal content: An application of probabilistic choice models in car acoustics

Hansen

Weber

2008

Acoust. Sci. & Tech.

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The rating of tonal content is not just a prevalent issue in the context of sound design but also in annoyance/noise problems. Two physical parameters influencing the evaluated tonal content are tone length and S/N-ratio. In order to integrate these parameters into a reliable, objective measure of the perceived tonal content of interior car noises the following experiments were conducted: Realistic ''howling,'' i.e. the tonal content, in interior car noise were presented with variations in tone length and S/N ratio. Thirteen stimuli were judged by 41 subjects in a complete pair comparison. It was shown that subjective judgments can be modeled by probabilistic choice models quite well. An one-dimensional choice model, i.e. the BTL model, must be rejected in favor of a more general elimination-by-aspect model. The results are the following: (1) The subject's decision aspects are identified by modeling the choice behavior: A non-howling aspect describes the sound evoking a sensation not described by the howling adjective and a pitch-salience aspect indicates the equivalent S/N-ratio of a tonal component. No subjective duration aspect was found. (2) The log-ratio scale obtained yields a constant factor for doubling the length in an interval from 250 ms to 2,000 ms with equal level as well as a constant factor for each increase by 3 dB. Furthermore, the tonal content conception and implications thereof are introduced and discussed.

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Continuous judgment of level-fluctuating sounds and the relationship between overall loudness and instantaneous loudness

Cited by 58 publications

References 6 publications

Relative Contribution of Translational and Rotational Vibration to Discomfort

Relative Contribution of Translational and Rotational Vibration to Discomfort

Modeling Soundscape Pleasantness Using perceptual Assessments and Acoustic Measurements Along Paths in Urban Context

The influence of tone length and S/N-ratio on the perception of tonal content: An application of probabilistic choice models in car acoustics

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