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| 2. |
- Schenkman, Bo N., et al.
(författare)
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Human echolocation : Pitch versus loudness information
- 2011
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Ingår i: Perception. - : SAGE Publications. - 0301-0066 .- 1468-4233. ; 40:7, s. 840-852
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Tidskriftsartikel (refereegranskat)abstract
- Blind persons emit sounds to detect objects by echolocation. Both perceived pitch and perceived loudness of the emitted sound change as they fuse with the reflections from nearby objects: Blind persons generally are better than sighted at echolocation, but it is unclear whether this superiority is related to detection of pitch, loudness, or both. We measured the ability of twelve blind and twenty-five sighted listeners to determine which of two sounds, 500 ms noise bursts, that had been recorded in the presence of a reflecting object in a room with reflecting walls using an artificial head. The sound pairs were original recordings differing in both pitch and loudness, or manipulated recordings with either the pitch or the loudness information removed. Observers responded using a 2AFC method with verbal feedback. For both blind and sighted listeners the performance declined more with the pitch information removed than with the loudness information removed. In addition, the blind performed clearly better than the sighted as long as the pitch information was present, but not when it was removed. Taken together, these results show that the ability to detect pitch is a main factor underlying high performance in human echolocation.
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| 3. |
- Angelov, Angel G., et al.
(författare)
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Four-decision tests for stochastic dominance, with an application to environmental psychophysics
- 2019
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Ingår i: Journal of mathematical psychology (Print). - : Elsevier. - 0022-2496 .- 1096-0880. ; 93
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Tidskriftsartikel (refereegranskat)abstract
- If the survival function of a random variable X lies to the right of the survival function of a random variable Y, then X is said to stochastically dominate Y. Inferring stochastic dominance is particularly complicated because comparing survival functions raises four possible hypotheses: identical survival functions, dominance of X over Y, dominance of Y over X, or crossing survival functions. In this paper, we suggest four-decision tests for stochastic dominance suitable for paired samples. The tests are permutation-based and do not rely on distributional assumptions. One-sided Cramér–von Mises and Kolmogorov–Smirnov statistics are employed but the general idea may be utilized with other test statistics. The power to detect dominance and the different types of wrong decisions are investigated in an extensive simulation study. The proposed tests are applied to data from an experiment concerning the individual’s willingness to pay for a given environmental improvement.
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| 4. |
- Alvarsson, Jesper J., et al.
(författare)
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Stress Recovery during Exposure to Nature Sound and Environmental Noise
- 2010
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Ingår i: International Journal of Environmental Research and Public Health. - Basel, Schweiz : MDPI Publishing. - 1660-4601 .- 1661-7827. ; 7:3, s. 1036-1046
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Tidskriftsartikel (refereegranskat)abstract
- Research suggests that visual impressions of natural compared with urban environments facilitate recovery after psychological stress. To test whether auditory stimulation has similar effects, 40 subjects were exposed to sounds from nature or noisy environments after a stressful mental arithmetic task. Skin conductance level (SCL) was used to index sympathetic activation, and high frequency heart rate variability (HF HRV) was used to index parasympathetic activation. Although HF HRV showed no effects, SCL recovery tended to be faster during natural sound than noisy environments. These results suggest that nature sounds facilitate recovery from sympathetic activation after a psychological stressor.
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| 5. |
- Axelsson, Östen, et al.
(författare)
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A principal components model of soundscape perception
- 2010
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 128:5, s. 2836-2846
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
- Axelsson, Östen, et al.
(författare)
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A Swedish instrument for measuring soundscape quality
- 2009
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Ingår i: Euronoise 2009. - Edinburgh : Institute of Acoustics.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In 2008 the International Organization for Standardization (ISO) decided to put together a new expert working group ISO/TC 43/SC 1/WG 54 named “Perceptual assessment of soundscape quality”. The purpose of this expert group is to propose the first ever, international standard on how to measure the perceived quality of soundscapes, by means of questionnaire techniques. This work is chiefly motivated by a need to harmonise methods in soundscape research internationally in order to improve the comparability of research results across countries and over time. Within the Swedish research program Soundscape Support to Health, the present authors developed such a technique based on field work and laboratory studies. In the present paper we present research in which we validated our initial findings and finalised our questionnaire protocol. We propose that the measurement of perceived soundscape quality must include: (1) identification of perceived sounds sources, such as, technological sounds, human sounds, and natural sounds, (2) classification of soundscape quality on a good–bad scale, and (3) qualitative measurement of a set of eight perceived-soundscape attributes defined in a two-dimensional Pleasantness–Eventfulness measurement model.
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| 7. |
- Axelsson, Östen, 1971-
(författare)
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Aesthetic Appreciation Explicated
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present doctoral thesis outlines a new model in psychological aesthetics, named the Information-Load Model. This model asserts that aesthetic appreciation is grounded in the relationship between the amount of information of stimuli and people’s capacity to process this information. This relationship results in information load, which in turn creates emotional responses to stimuli. Aesthetic appreciation corresponds to an optimal degree of information load. Initially, the optimal degree is relatively low. As an individual learns to master information in a domain (e.g., photography), the degree of information load, which corresponds to aesthetic appreciation, increases. The present doctoral thesis is based on three empirical papers that explored what factors determine aesthetic appreciation of photographs and soundscapes. Experiment 1 of Paper I involved 34 psychology undergraduates and 564 photographs of various motifs. It resulted in a set of 189 adjectives related to the degree of aesthetic appreciation of photographs. The subsequent experiments employed attribute scales that were derived from this set of adjectives. In Experiment 2 of Paper I, 100 university students scaled 50 photographs on 141 attribute scales. Similarly, in Paper II, 100 university students scaled 50 soundscapes on 116 attribute scales. In Paper III, 10 psychology undergraduates and 5 photo professionals scaled 32 photographs on 27 attribute scales. To explore the underlying structure of the data sets, they were subjected to Multidimensional Scaling and Principal Components Analyses. Four general components, related to aesthetic appreciation, were found: Familiarity, Hedonic Tone, Expressiveness, and Uncertainty. These components result from the higher-order latent factor Information Load that underlies aesthetic appreciation.
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| 8. |
- Axelsson, Östen, et al.
(författare)
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On sound source identification and taxonomy in soundscape research : Paper No. in10_780
- 2010
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Ingår i: Inter Noise 2010. - Lisbon, Portugal : Portuguese Acoustical Society.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Sound source identification is typically the first step in a soundscape study. For comparability, a standardized sound source taxonomy and data collection methods are needed. Sound sources typically form three main categories: technological, human and natural sounds (e.g., road traffic, voices, and singing birds). These categories are meaningfully related to emotional responses to soundscapes. Technological sounds are typically judged unpleasant, natural sounds pleasant, whereas human sounds are eventful. Based on our empirical results we discuss how detailed a sound source taxonomy needs to be. We illustrate and conclude, it must state basic principles for how to categorize sound sources, and include clear examples without aiming to be exhaustive. Although standardized, related data collection methods must be flexible and allow adaption to unforeseen circumstances.
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| 9. |
- Axelsson, Östen, et al.
(författare)
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Soundscape assessment.
- 2005
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Ingår i: The Journal of the Acoustical Society of America. - 0001-4966. ; 117:4, s. 2591-2592
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In order to improve the quality of the soundscape it is necessary to know its descriptive and evaluative properties, and the relationships between these properties. This was explored in a listening experiment with 100 participants (48 women, 52 men; mean age 25,6 years). Each participant scaled 5 out of 50 soundscapes with regard to 116 single verbal attributes, using a visual analogue scale of agreeableness. In addition, acoustical properties of the soundscapes were assessed. A principal component analysis identified two major evaluative components, labeled Hedonic Tone and Eventfulness. Furthermore it was found that the mere presence of common sound sources, regardless of sound level, correlated significantly with these evaluative components. Technological sounds (e.g., traffic noise) were negatively associated with both Hedonic Tone and Eventfulness, while a positive association was found between Hedonic Tone and sounds of nature (e.g., bird song), and a positive association was found between Eventfulness and human sounds (e.g., human voices). These relationships lead to the hypothesis that introduction of nature and human sounds, in combination with the reduction of technological sounds may improve the quality of soundscapes considerably.
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| 10. |
- Axelsson, Östen, et al.
(författare)
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Water features and acoustic diversity of urban parks
- 2011
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 0001-4966 .- 1520-8524. ; 130:4, s. 2533-2533
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Water features are well-acknowledged in architecture and urban planning for their visual characteristics. But, how do water features contribute to acoustic diversity and soundscape quality? Visitors in an urban park were recruited to complete a questionnaire on how they perceived the park including its soundscape. Meanwhile, the soundscape was manipulated by turning a fountain on or off at irregular hours. The fountain sounds had a positive effect on soundscape quality in an area close to the fountain, by masking background road-traffic noise. The fountain sound also masked other natural sounds, which may have a negative influence on acoustic diversity and soundscape quality. In addition, some participants may have mistaken the fountain sounds for distant road-traffic noise. Hence, when introducing a water feature in an urban park it is necessary to consider the acoustic characteristics of the water sounds, as well as the placement of the water feature.
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