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It may be difficult to determine whether a dichotic lag-click points to the left or right when preceded by a diotic lead-click. Previous research suggests that this loss of spatial information is most prominent at inter-click intervals (ICIs) <10 ms. However, a study by Nilsson, Tirado, and Szychowska [(2019). J. Acoust. Soc. Am. 145, 512–524] found support for loss of spatial information in lag-clicks at much longer ICIs using a stimulus setup differing from those in previous research. The present study used a setup similar to that of the Nilsson, Tirado, and Szychowska study [(2019). J. Acoust. Soc. Am. 145, 512–524] to measure 13 listeners' ability to lateralize (left versus right) and detect (present versus absent) the lag-click in lead–lag click pairs with ICIs of 6–48 ms. The main finding was distinct individual differences in performance. Some listeners could lateralize lag-clicks all the way down to their detection threshold, whereas others had lateralization thresholds substantially higher than their detection thresholds, i.e., they could not lateralize lag-clicks that they could easily detect. Two such listeners trained for 30 days and managed to improve their lateralization thresholds to reach their detection thresholds, but only at longer ICIs (>20 ms), suggesting different mechanisms underlying lag-click lateralization at short versus long ICIs. [ABSTRACT FROM AUTHOR]

Listeners have limited access to spatial information in lagging sound, a phenomenon known as discrimination suppression. It is unclear whether discrimination suppression works differently for interaural time differences (ITDs) and interaural level differences (ILDs). To explore this, three listeners assessed the lateralization (left or right) and detection (present or not) of lag clicks with a large fixed ITD (350 μs) or ILD (10 dB) following a diotic lead click, with inter-click intervals (ICIs) of 0.125–256 ms. Performance was measured on a common scale for both cues: the lag–lead amplitude ratio [dB] at 75% correct answers. The main finding was that the lateralization thresholds, but not detection thresholds, were more strongly elevated for ITD-only than ILD-only clicks at intermediate ICIs (1–8 ms) in which previous research has found the strongest discrimination suppression effects. Altogether, these findings suggest that discrimination suppression involves mechanisms that make spatial information conveyed by lag-click ITDs less accessible to listeners than spatial information conveyed by lag-click ILDs. [ABSTRACT FROM AUTHOR]

Many blind people learn to use sound reflections to localize objects. However, precedence-effect research has reported evidence both for and against the possibility to improve lateralization of lag clicks preceded by lead clicks. This training study used stimuli more relevant to human echolocation than did previous training studies. One participant, the author, practiced lateralizing a lag-click inter-aural level difference (ILD) of 10 dB for 60 days, with performance measured in the lag–lead peak amplitude ratio at threshold. Clear improvements were observed at interclick intervals of 2–18 ms, suggesting that extracting a large lag-click ILD may improve with practice. [ABSTRACT FROM AUTHOR]

Water fountains are potential tools for soundscape improvement, but little is known about their perceptual properties. To explore this, sounds were recorded from 32 fountains installed in urban parks. The sounds were recorded with a sound-field microphone and were reproduced using an ambisonic loudspeaker setup. Fifty-seven listeners assessed the sounds with regard to similarity and pleasantness. Multidimensional scaling of similarity data revealed distinct groups of soft variable and loud steady-state sounds. Acoustically, the soft variable sounds were characterized by low overall levels and high temporal variability, whereas the opposite pattern characterized the loud steady-state sounds. The perceived pleasantness of the sounds was negatively related to their overall level and positively related to their temporal variability, whereas spectral centroid was weakly correlated to pleasantness. However, the results of an additional experiment, using the same sounds set equal in overall level, found a negative relationship between pleasantness and spectral centroid, suggesting that spectral factors may influence pleasantness scores in experiments where overall level does not dominate pleasantness assessments. The equal-level experiment also showed that several loud steady-state sounds remained unpleasant, suggesting an inherently unpleasant sound character. From a soundscape design perspective, it may be advisable to avoid fountains generating such sounds. [ABSTRACT FROM AUTHOR]

Studies of effects on speech intelligibility from aircraft noise in outdoor places are currently lacking. To explore these effects, first-order ambisonic recordings of aircraft noise were reproduced outdoors in a pergola. The average background level was 47 dB LAeq. Lists of phonetically balanced words (LASmax,word=54 dB) were reproduced simultaneously with aircraft passage noise (LASmax,noise=72-84 dB). Twenty individually tested listeners wrote down each presented word while seated in the pergola. The main results were (i) aircraft noise negatively affects speech intelligibility at sound pressure levels that exceed those of the speech sound (signal-to-noise ratio, S/N<0), and (ii) the simple A-weighted S/N ratio was nearly as good an indicator of speech intelligibility as were two more advanced models, the Speech Intelligibility Index and Glasberg and Moore's [J. Audio Eng. Soc. 53, 906-918 (2005)] partial loudness model. This suggests that any of these indicators is applicable for predicting effects of aircraft noise on speech intelligibility outdoors. [ABSTRACT FROM AUTHOR]

Distance to a sound source can be accurately estimated solely from auditory information. With a sound source such as a train that is passing by at a relatively large distance, the most important auditory information for the listener for estimating its distance consists of the intensity of the sound, spectral changes in the sound caused by air absorption, and the motion-induced rate of change of intensity. However, these cues are relative because prior information/experience of the sound source-its source power, its spectrum and the typical speed at which it moves-is required for such distance estimates. This paper describes two listening experiments that allow investigation of further prior contextual information taken into account by listeners-viz., whether they are indoors or outdoors. Asked to estimate the distance to the track of a railway, it is shown that listeners assessing sounds heard inside the dwelling based their distance estimates on the expected train passby sound level outdoors rather than on the passby sound level actually experienced indoors. This form of perceptual constancy may have consequences for the assessment of annoyance caused by railway noise. [ABSTRACT FROM AUTHOR]

There is a need for a model that identifies underlying dimensions of soundscape perception, and which may guide measurement and improvement of soundscape quality. With the purpose to develop such a model, a listening experiment was conducted. One hundred listeners measured 50 excerpts of binaural recordings of urban outdoor soundscapes on 116 attribute scales. The average attribute scale values were subjected to principal components analysis, resulting in three components: Pleasantness, eventfulness, and familiarity, explaining 50, 18 and 6% of the total variance, respectively. The principal-component scores were correlated with physical soundscape properties, including categories of dominant sounds and acoustic variables. Soundscape excerpts dominated by technological sounds were found to be unpleasant, whereas soundscape excerpts dominated by natural sounds were pleasant, and soundscape excerpts dominated by human sounds were eventful. These relationships remained after controlling for the overall soundscape loudness (Zwicker's N10), which shows that 'informational' properties are substantial contributors to the perception of soundscape. The proposed principal components model provides a framework for future soundscape research and practice. In particular, it suggests which basic dimensions are necessary to measure, how to measure them by a defined set of attribute scales, and how to promote high-quality soundscapes. [ABSTRACT FROM AUTHOR]

On the basis of this study it cannot be ruled out that the appraisal of the noise affects the association between air and road traffic noise exposure and children's health and cognition. However, the conclusion is limited due to the relatively small group of annoyed children, which may have influenced our group comparisons. Furthermore, the observed relation between annoyance and perceived health is possibly biased due to the fact that both were measured within the same questionnaire. These are the main conclusions of a cross-sectional multi-center study carried out among 2,844 schoolchildren (age 9-11 years) attending 89 primary schools around three European airports. The aim was to investigate how annoyance affects the relation between air and road traffic noise exposure and children's health and cognition. Different, sometimes competing, working mechanisms of how noise affects children's health are suggested. Some effects are supposed to be precipitated through (chronic) stress, while others may arise directly. There is still no theory that can adequately account for the circumstances in which noise will affect cognitive performance. [ABSTRACT FROM AUTHOR]

An approach is proposed to shed light on the mechanisms underlying human perception of environmental sound that intrudes in everyday living. Most research on exposure-effect relationships aims at relating overall effects to overall exposure indicators in an epidemiological fashion, without including available knowledge on the possible underlying mechanisms. Here, it is proposed to start from available knowledge on audition and perception to construct a computational framework for the effect of environmental sound on individuals. Obviously, at the individual level additional mechanisms (inter-sensory, attentional, cognitive, emotional) play a role in the perception of environmental sound. As a first step, current knowledge is made explicit by building a model mimicking some aspects of human auditory perception. This model is grounded in the hypothesis that long-term perception of environmental sound is determined primarily by short notice-events. The applicability of the notice-event model is illustrated by simulating a synthetic population exposed to typical Flemish environmental noise. From these simulation results, it is demonstrated that the notice-event model is able to mimic the differences between the annoyance caused by road traffic noise exposure and railway traffic noise exposure that are also observed empirically in other studies and thus could provide an explanation for these differences. [ABSTRACT FROM AUTHOR]

Since annoyance reactions of children to environmental noise have rarely been investigated, no source specific exposure-response relations are available. The aim of this paper is to investigate children's reactions to aircraft and road traffic noise and to derive exposure-response relations. To this end, children's annoyance reactions to aircraft and road traffic noise in both the home and the school setting were investigated using the data gathered in a cross-sectional multicenter study, carried out among 2844 children (age 9-11 years) attending 89 primary schools around three European airports. An exposure-response relation was demonstrated between exposure to aircraft noise at school (LAeq,7-23 h) and severe annoyance in children: after adjustment for confounders, the percentage severely annoyed children was predicted to increase from about 5.1% at 50 dB to about 12.1% at 60 dB. The findings were consistent across the three samples. Aircraft noise at home (LAeq,7-23 h) demonstrated a similar relation with severe annoyance. Children attending schools with higher road traffic noise (LAeq,7-23 h) were more annoyed. Although children were less annoyed at levels above 55 dB, the shapes of the exposure-response relations found among children were comparable to those found in their parents. [ABSTRACT FROM AUTHOR]

A common indicator of effectiveness for roadside noise barriers is the reduction in A-weighted sound pressure level (LA). The present experimental study considered alternative indicators using an annoyance-reduction criterion. A large number of 8 s experimental sounds were created from binaural recordings conducted at various distances from a highway at a location with a 4.6 m high roadside barrier (barrier sounds) and at a location along the same road with no barrier (nonbarrier sounds). Eighteen listeners scaled the annoyance of the experimental sounds with the method of magnitude estimation. The barrier sounds recorded 10–45 m from the road and nonbarrier sounds recorded 50–200 m from the road were of similar LA. Despite this, the barrier sounds were found to be more annoying than the nonbarrier sounds. The annoyance difference corresponded to approximately a 3 dB increase in LA and was mainly related to the barrier sounds’ higher relative level of low-frequency sound. This suggests that LA reduction may not be a valid indicator of the annoyance reduction caused by a noise barrier. The loudness level (ISO 532B) and a low-frequency corrected sound pressure level (LA*) were found to be better than LA as indicators of the barrier’s annoyance-reduction efficiency. [ABSTRACT FROM AUTHOR]

Questionnaire studies were conducted in a residential area before and after the erection of a 2.25 m high noise barrier of conventional type along a heavily traveled road (19 600 vehicles/24 h). The interval between studies was two years. Houses closest to the barrier received a sound-level reduction from ∼70.0 to 62.5 dB Lden at the most exposed facade. The sound-level reduction decreased with distance to the road, and was negligible for houses at more than 100 m distance. Up to this distance, the noise barrier reduced residents’ noise annoyance outdoors and indoors as well as improved speech communication outdoors. Indoors, speech communication and sleep disturbance were slightly but nonsignificantly improved. Predictions of the number of annoyed persons from published exposure-response curves (in Lden) agreed with the percentage of residents being annoyed when indoors, before and after the barrier. Conversely, the percentage of residents being annoyed when outdoors clearly exceeded the predictions. These results suggest that these exposure-response curves may be used in predicting indoor situations, but they should not be applied in situations where outdoor annoyance is at focus. [ABSTRACT FROM AUTHOR]