2,334 research outputs found

    Perception of soundscapes : an interdisciplinary approach

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    This paper takes an overall view of findings from the Positive Soundscape Project, a large inter-disciplinary soundscapes study. Qualitative fieldwork (soundwalks and focus groups) have found that soundscape perception is influenced by cognitive effects such as the meaning of a soundscape and its components, and how information is conveyed by a soundscape, for example on the behaviour of people within the soundscape. Three significant clusters were found in the language people use to describe soundscapes: sound sources, sound descriptors and soundscape descriptors. Results from listening tests and soundwalks have been integrated to show that the two principal dimensions of soundscape emotional response seem to be calmness and vibrancy. Further, vibrancy seems to have two aspects: organisation of sounds and changes over time. The possible application of the results to soundscape assessment and design are briefly discussed

    Soundscape descriptors and a conceptual framework for developing predictive soundscape models

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    Soundscape exists through human perception of the acoustic environment. This paper investigates how soundscape currently is assessed and measured. It reviews and analyzes the main soundscape descriptors in the soundscape literature, and provides a conceptual framework for developing predictive models in soundscape studies. A predictive soundscape model provides a means of predicting the value of a soundscape descriptor, and the blueprint for how to design soundscape. It is the key for implementing the soundscape approach in urban planning and design. The challenge is to select the appropriate soundscape descriptor and to identify its predictors. The majority of available soundscape descriptors are converging towards a 2-dimensional soundscape model of perceived affective quality (e.g., Pleasantness–Eventfulness, or Calmness–Vibrancy). A third potential dimension is the appropriateness of a soundscape to a place. This dimensions provides complementary information beyond the perceived affective quality. However, it depends largely on context, and because a soundscape may be appropriate to a place although it is poor, this descriptor must probably not be used on its own. With regards to predictors, or soundscape indicators, perceived properties of the acoustic environment (e.g., perceived sound sources) are winning over established acoustic and psychoacoustic metrics. To move this area forward it is necessary that the international soundscape community comes together and agrees on relevant soundscape descriptors. This includes to agree on numerical scales and assessment procedures, as well as to standardize them

    Noise and Vibration Control in the Built Environment

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    With global urbanization rapidly rising and the increasing need of high-quality built environments, the requirement of achieving improved sound quality, both for outdoor and indoor environments, has received a lot of attention. This Special Issue collection reflects the current state of the art, with 12 papers covering environmental acoustics; the influence of soundscapes on people’s behavior; soundscape pleasantness estimation; tranquility; perceived quality of sonic environments; sound and vibration-related health complaints concerning tramways; and the disturbance of construction machines; as well as in building and room acoustics, including natural ventilation-enabling façade noise control devices; the effect of external shading devices; rating method of airborne sound insulation; water supply and drainage noise, and the effect of diffusive surfaces in auditoria. Some papers cover research on the engineering aspects of sound and vibration, such as sound propagation and noise control techniques, as well as perception aspects of sound, such as indoor acoustic comfort and environmental soundscapes. The book is prefaced by Prof. S Wu, entitled ‘Sustainable Urban Sound Environment’

    Subjective listening experiments for annoyance investigation

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    Noise limits and guidelines that consider only the sound pressure level or the loudness of noises are not efficient in protecting people from all the adverse effects of noise. Other physical characteristics, e.g., tonality, modulation, and frequency content, should also be considered, especially when the noise level is low and it cannot cause hearing risk, but might lead to annoyance and disturbance. Annoying noises have an impact on health and well-being, but this impact and its relationship with the physical properties have not been sufficiently studied. Subjective annoyance caused by noises like those we experience in living spaces and offices should be further investigated via psychoacoustic laboratory experiments. The primary aim of this work was to develop systematic, effective, and reliable methodology to perform this type of psychoacoustic tests. The secondary aim was to investigate the objective metrics that best predict subjective annoyance in four typical noise conditions: ventilation noise in office spaces, traffic noise in homes, neighbors’ noise in homes, and noises with tonal components in homes. The main result was the development of the methodology, which in turn enabled us to define our own standards and guidelines. Furthermore, we identified the objective metrics that best correlated with subjective annoyance in each one of the four studied noise situations. In offices, five metrics predicted subjective ratings reasonably well. Noise with sound energy at higher frequencies was less tolerated. Noise with a slope of -7 dB per octave band increment resulted in the highest satisfaction. In dwellings, related to neighbors’ living sounds, four metrics of airborne sound insulation performed well to predict annoyance. We demonstrated that 50–80 Hz bands should not be included in the objective rating. In dwellings, related to five types of traffic noise transmitted through façade elements, one metric Rw+C50–3150 performed significantly better than the others. The last experiment proved that tonality is not properly considered in current standards and noise guidelines. The performed psychoacoustic research demonstrated that other physical properties than the sound pressure level should be considered when assessing noise annoyance, and it provided evidence to the objective metrics that would make noise guidelines more efficient with respect to health protection.Subjektiivisia kuuntelukokeita hĂ€iritsevyyden tutkimiseksi Melurajat ja ohjeet suojelevat ihmisiĂ€ melun haitallisista vaikutuksista, mutta ne ottavat enimmĂ€kseen huomioon vain melun ÀÀnenpainetason tai voimakkuuden. Muut fyysiset ominaisuudet, kuten kapeakaistaisuus, modulaatio ja taajuussisĂ€ltö, joilla on selvĂ€ vaikutus subjektiiviseen kokemukseen ja hĂ€iritsevyyteen, jĂ€tetÀÀn usein huomiomatta. ÄrsyttĂ€vĂ€t ÀÀnet saattavat noudattaa lakia niiden kielteisistĂ€ vaikutuksista huolimatta, koska niiden ÀÀnenpainetaso ei ylitĂ€ yhtÀÀn melurajaa. Asuintilojen ja toimistojen melun aiheuttamaa subjektiivista Ă€rsytystĂ€ tulisi tutkia tarkemmin psykoakustisten laboratoriokokeiden avulla. Työn ensisijaisena tavoitteena oli kehittÀÀ jĂ€rjestelmĂ€llinen, tehokas ja luotettava menetelmĂ€ tĂ€mĂ€n tyyppisten psykoakustisten testien suorittamiseksi. LisĂ€ksi selvitettiin, mitĂ€ muita objektiivisia mittareita, kuin ÀÀnenpainetaso tai ÀÀnenvoimakkuus, ennustavat parasta subjektiivista Ă€rsytystĂ€ ja hĂ€iritsevyyttĂ€. TyössĂ€ tutkittiin neljÀÀ tyypillistĂ€ meluolosuhdetta: toimistotilojen ilmanvaihdonÀÀniĂ€, kaupungin liikenteen melua kodeissa, naapurin melua kodeissa, ja kapeakaistaisia komponentteja sisĂ€ltĂ€vÀÀ melua. PÀÀtuloksena oli menetelmĂ€n kehittĂ€minen, joka mahdollisti omien standardien ja toimintaohjeiden mÀÀrittĂ€misen. LisĂ€ksi tunnistettiin objektiiviset mittarit, jotka korreloivat paremmin subjektiivisen hĂ€iritsevyyden kanssa kussakin neljĂ€stĂ€ tutkitusta melutilanteesta. Toimistoissa viisi mittaria ennusti kohtuullisen hyvin subjektiivisia luokituksia. Kohinaa, joka kuului korkeammilla taajuuksilla toimivalla ÀÀnenergialla, siedettiin vĂ€hemmĂ€n. Asunnoissa, kun asumisÀÀniĂ€ syntyy naapurin asunnossa, neljĂ€ ilmaÀÀneneristysmittaria toimi hyvin ennustamaan asukkaiden subjektiivista Ă€rsytystĂ€. Osoitettiin, ettĂ€ 50–80 Hz: n kaistoja ei pitĂ€isi sisĂ€llyttÀÀ objektiiviseen luokitukseen. Myös asunnoissa, liittyen viitteen eri liikennemeluun kantautumassa sisĂ€tilaan julkisivuelementtien kautta, yksi metrinen Rw+C50–3150 toimi huomattavasti paremmin kuin muut. Viimeinen koe osoitti, ettĂ€ tonaalisuutta ei oteta asianmukaisesti huomioon nykyisissĂ€ standardeissa ja meluohjeissa. TĂ€mĂ€ tutkimus osoitti, ettĂ€ oikein suoritetut psykoakustiset kokeet tarjoavat laadullista ja mÀÀrĂ€llistĂ€ tietoa subjektiivisesta hĂ€iritsevyydestĂ€, ja ettĂ€ nĂ€iden tietojen perusteella voidaan mÀÀrittÀÀ objektiiviset mittarit, jotka tekisivĂ€t ohjearvoista tehokkaampia melun haitallisilta vaikutuksilta suojauduttaessa

    Implementing Observation Protocols: Lessons for K-12 Education From the Field of Early Childhood

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    Examines issues for implementing standardized observation protocols for teacher evaluations. Makes recommendations based on lessons from preschool, such as the need to show empirical links between teacher performance and student learning and development

    Soundscape design of water features used in outdoor spaces where road traffic noise is audible

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    This research focused on the soundscape design of a wide range of small to medium sized water features (waterfalls, fountains with upward jet(s), and streams) which can be used in gardens or parks for promoting peacefulness and relaxation in the presence of road traffic noise. Firstly, the thesis examined the audio-visual interaction and perceptual assessment of water features, including the semantic components and the qualitative categorisation and evocation of water sounds; and secondly, the thesis investigated the effectiveness of the water features tested in promoting relaxation through sound mapping. Different laboratory tests were carried out, and these included paired comparison tests (audio-only, visual-only and audio-visual tests), semantic differential tests, as well as tests aimed at the qualitative categorisation and evocation of water features. Sound maps of the water generated sounds were developed through the use of propagation models based on either point or line sources. Three acoustic zones (‘water sounds dominant zone’, ‘optimum zone’ and ‘RTN dominant zone’ (RTN: road traffic noise)) were defined in the maps as the zones where relaxation/pleasantness can be promoted over a 20 m × 20 m area for different road traffic noise levels. Paired comparisons highlighted the interdependence between uni-modal (audio-only or visual-only) and bi-modal (audio-visual) perception, indicating that equal attention should be given to the design of both stimuli. In general, natural looking features tended to increase preference scores (compared to audio-only paired comparison scores), while manmade looking features decreased them. Semantic descriptors showed significant correlations with preferences and were found to be more reliable design criteria than physical parameters. A principal component analysis identified three components within the nine semantic attributes tested: “emotional assessment,” “sound quality,” and “envelopment and temporal variation.” The first two showed significant correlations with audio-only preferences, “emotional assessment” being the most important predictor of preferences, and its attributes naturalness, relaxation, and freshness also being significantly correlated with preferences. Categorisation results indicated that natural stream sounds are easily identifiable (unlike waterfalls and fountains), while evocation results showed no unique relationship with preferences. The results of sound maps indicated that small to medium sized water features can be used mainly in environments where road traffic noise levels are equal or lower than 65 dBA

    Subjective Estimation of Airborne Sound Insulation

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    This study explores airborne sound insulation as an objective and subjective measure. The concept of this study starts with a hypothesis that there is a need to assess airborne sound insulation in terms of a hearing related measure. Firstly, this study examines how the airborne sound insulation is determined in current standards and how it is affected using different sound signals. To quantify the sound insulation effect of different sound signals and to allow investigating the results numerically, a series of measurements have been carried out. To assess the differences in the evaluation of source signals, electronic filters were generated as well as subjective tests were conducted. The overall results for each research topic can be summarised as follows: Airborne sound insulation determined according to current standards, does not reflect the subjectively perceived sound insulation. It was proven that sound pressure level difference as well as loudness level difference does not relate well to subjectively assessed sound insulation. The introduced loudness level based model correctly depicts the experimental results of the loudest and quietest sound samples as well as the individual frequency dips in the airborne sound insulation. Results of field measurements show that subjectively assessed airborne sound insulation differ from objectively judged airborne sound insulation using descriptors of current standards. Measurements made with different sound signals indicate that the subjectively judged sound insulation is depending on the type of source signal. The model correctly identifies dif-ferent sound signals relating a measure of “reliable” and “not reliable” in terms of a subjective assessed measure with respect to the predicted value. Thus, the model describes the probability that a measured or computed airborne sound insulation corresponds to the subjectively assessed airborne sound insulation

    Mandarin Chinese translation of the ISO-12913 soundscape attributes to investigate the mechanism of soundscape perception in urban open spaces

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    This study is part of a global collaboration to translate the soundscape attributes proposed in ISO/TS 12913-2:2018, which aims to standardise soundscape research globally. Cross-referencing results from two independent expert panels produced a set of eight soundscape attributes that were subsequently experimentally verified, forming a reliable questionnaire for soundscape characterisation in Mandarin Chinese. Employing the as-developed questionnaire, ex situ auditory-only soundscape perception experiments were carried out with 27 soundscape recordings from urban open spaces in the United Kingdom. The soundscape perception scale was used to evaluate participants' experiences, which were then projected into two dimensions of soundscape perception, pleasantness and eventfulness, following protocols from ISO 12913-3:2019. Physical and psychoacoustic parameters, as well as the characteristics of the sound sources, were extracted from the recordings. These parameters were used together to describe the soundscape characteristics of the recordings. Principal component analysis revealed that, when individuals are exposed to urban open spaces, the salient sound source becomes the foreground focus of attention, informing them to perceive the soundscape. Beyond this, perception stimulation is further based on the acoustic characteristics of the soundscape. Regression analysis investigated factors for pleasantness and eventfulness. For pleasantness, the overall S95 had a significant negative effect while birdsong was beneficial. With regard to eventfulness, mechanical sound had a detrimental impact, while the number of salient sound source types and the overall F50 had a positive impact. Furthermore, this study founds that certain types of sound sources make the sound more recognisable as a foreground sound, thereby stimulating perception, while others may be ignored as background sounds but still contribute to the perception through their acoustic characteristics

    Developing acoustic rating quantities using experimental psychoacoustic data

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    ABSTRACT Noise is frequently present in our daily lives. Noise is encountered both indoors and outdoors, in various environments such as at home, in traffic and at work place. Excessive noise causes annoyance and other negative health effects. Acoustical quantities are needed to quantify the properties of noise as well as to determine sound insulation capabilities of structures. Psychoacoustic experiments have revealed that the existing quantities do not always correspond well to subjective perception. The objective of this thesis was to develop acoustical quantities that correspond better to subjective perception than the existing quantities by deploying psychoacoustic data. This thesis contains four publications. Three publications consider developing quantities for rating sound insulation, and the fourth deals with annoyance penalty for periodic amplitude modulated sounds. Sound insulation of a structure (e.g. a wall, window, floor, or facžade) is measured in several one-third octave bands. To simplify the information gathered with sound insulation measurements, and to enable easier comparison between structures as well as to facilitate the imposition of legislative requirements, single-number quantities have been developed for rating sound insulation of different structures, such as described in standards ISO 717-1 and ISO 717-2. It is important that these simplified quantities are based on psychoacoustical experiments to ensure adequate correspondence to subjective perception. The development of the existing quantities has not taken this aspect fully into account. In this thesis, single-number quantities for rating sound insulation were developed using mathematical optimization and psychoacoustic data from three already published experiments. New reference spectra were derived for various living sounds for airborne sound insulation, typical domestic impact sounds for impact sound insulation as well as for several road traffic spectra for facžade sound insulation. The results showed that an optimized reference spectrum resulting in well-performing single-number quantity could be derived for each studied sound type. The developed mathematical optimization scheme enables systematic development of new reference spectra, which are based on scientific evidence. Amplitude modulated sounds (e.g. road traffic noise and wind turbine noise) have been found to cause more annoyance than steady-state sounds. A penalty can be added to the measured sound level to take into account the increase in annoyance due to modulation in sound. In this thesis, it was studied if a penalty is needed for periodically amplitude modulated wide-band general sounds having a low sound level by conducting a psychoacoustical experiment with 40 participants. The results showed the need for penalty for certain ranges of modulation frequencies and modulation depths for the studied sounds. The penalties increased with increasing modulation frequency and increasing modulation depth, which does not support using a constant penalty. The results of this thesis can be exploited in the improvement of future academic research, acoustical standards, and building regulations. TIIVISTELMÄ Melu on usein lĂ€snĂ€ pĂ€ivittĂ€isessĂ€ elĂ€mĂ€ssĂ€mme. Kohtaamme melua erilaisissa ympĂ€ristöissĂ€ kuten kotona, liikenteessĂ€a ja työpaikoilla. Liiallinen melu hĂ€iritsee, ja melun on todettu voivan vaikuttaa myös muilla tavoin negatiivisesti terveyteemme. Akustisten suureiden avulla voidaan mÀÀrittÀÀ melun ominaisuuksia sekĂ€ erilaisten rakenteiden ÀÀneneristyskykyĂ€ Psykoakustiset kokeet ovat tuoneet ilmi, ettĂ€ olemassa olevat suureet eivĂ€t aina vastaa riittĂ€vĂ€n hyvin subjektiivista kokemusta melun hĂ€iritsevyydestĂ€. TĂ€mĂ€n vĂ€itöskirjan tarkoituksena oli psykoakustista dataa hyödyntĂ€en kehittÀÀ akustisia suureita, jotka vastaavat subjektiivista kokemusta nykyisiĂ€ suureita paremmin. VĂ€itöskirjaja koostuu neljĂ€stĂ€ osajulkaisusta. Kolme julkaisuista kĂ€sittelee ÀÀneneristĂ€vyyden yksilukuarvojen kehitystĂ€, ja neljĂ€s jaksollisesti moduloitujen ÀÀnten hĂ€iritsevyyssanktion mÀÀrittĂ€mistĂ€. Rakenteen (esimerkiksi seinĂ€, ikkuna, lattia tai julkisivu) ÀÀneneristĂ€vyys mitataan kolmasosaoktaaveittain useammalla taajuuskaistalla. Monimutkaisen taajuuskaistainformaation yksinkertaistamiseksi on kehitetty yksilukuarvoja (esimerkiksi standardit ISO 717-1 ja ISO 717-2) eri rakenteiden vertailuun sekĂ€ mahdollistamaan rakennusmÀÀrĂ€ysten asettamisen. On tĂ€rkeÀÀ, ettĂ€ kehitetyt yksilukuarvot perustuvat psykoakustiseen tutkimusnĂ€yttöön, ja vastaavat riittĂ€vĂ€n hyvin subjektiivista hĂ€iritsevyyttĂ€. Nykyisten kĂ€ytössĂ€ olevien standaroitujen suureiden kehityksessĂ€ tĂ€tĂ€ ei ole tĂ€ysin huomioitu. TĂ€ssĂ€ vĂ€itöskirjassa ÀÀneneristĂ€vyyden yksilukuarvoja kehitettiin matemaattisen optimoinnin ja kolmessa jo aiemmin julkaistussa tutkimuksessa kerĂ€tyn psykoakustisen datan avulla. IlmaÀÀnen- ja askelÀÀnieristĂ€vyyden referenssispektrit johdettiin erilaisille asuinÀÀnille. Julkisivun ÀÀneneristĂ€vyydelle johdettiin referenssispektrit usealle eri tieliikennemeluspektrille. Tulokset osoittivat, ettĂ€ optimoitujen referenssispektrien avulla saadut yksilukuarvot suoriutuivat hyvin kullakin tutkitulla ÀÀnityypillĂ€. Kehitetty matemaattinen optimointimalli mahdollistaa tieteelliseen nĂ€yttöön perustuvien referenssispektrien ja tĂ€ten uusien yksilukuarvojen systemaattisen kehityksen. Amplitudimoduloitujen ÀÀnien kuten liikennemelun ja tuulivoimalamelun on havaittu hĂ€iritsevĂ€n enemmĂ€n kuin tasaisten ÀÀnien. Moduloinnin aiheuttama hĂ€iritsevyyden lisĂ€ys voidaan huomioida lisÀÀmĂ€llĂ€ mitattuun keskiÀÀnitasoon sanktio. TĂ€ssĂ€ vĂ€itöskirjassa tutkittiin, tarvitaanko sanktiota jaksollisesti vaihtelevalle laajakaistaiselle melulle, jonka ÀÀnitaso on matala. TĂ€tĂ€ tutkittiin toteuttamalla psykoakustinen kuuntelukoe, johon osallistui 40 koehenkilöÀ. Tulokset osoittivat, ettĂ€ sanktio voi olla tarpeen tietyllĂ€ modulaatiotaajuuden ja modulaatiosyvyyden arvoalueella. Sanktion suuruus kasvoi modulaatiotaajuuden ja modulaatiosyvyyden kasvaessa, mikĂ€ ei tue vakiosanktion kĂ€yttöÀ. TĂ€mĂ€n vĂ€itöskirjan tuloksia voidaan hyyödyntÀÀ tieteellisessĂ€ tutkimuksessa sekĂ€ akustisten standardien ja rakennusmÀÀrĂ€ysten kehittĂ€misessĂ€

    Understanding soundscape in public spaces : a case study in AkköprĂŒ Metro Station, Ankara

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    Ankara : The Department of Interior Architecture and Environmental Design, Ä°hsan Doğramacı Bilkent Univ., 2014.Thesis (Master's) -- Bilkent University, 2014.Includes bibliographical references leaves 56-60.In 2008, a working group of ISO/TC 43/SCI/WG 54 “Perceptual Assessment of Soundscape Quality of the International Organization for Standardization” was established and they published the first part of standardization “ISO 12913-1 Acoustics-Soundscape-Definition and conceptual framework” In their framework the acoustic environment divides into two main categories according to places; indoor and outdoor acoustic environment. The working group ISO/TC 43/SCI/WG 54 is being to standardize the methods and parameters of soundscape quality outdoors and point out both the negative and positive aspects of sounds environment as perceived by people. Besides the soundscape quality outdoors, indoors are also needed to be studying in the field. This study has been designed to understand the indoor acoustic environment of the metro station which is chosen as a public space. Aim of this study is to find out both negative and positive aspects of indoor acoustic environment as perceived by users in metro station. In order to compare outdoor and indoor soundscape qualities, AkköprĂŒ Metro Station and its immediate surrounding were chosen as a case study in Ankara, Turkey. The park shared the same environment with metro station was chosen as an outdoor environment/open public space. Entrance of the metro station was chosen as a semi open public space and the platform of the metro station was chosen as an indoor environment/enclosed public space. Within “a degree of enclosure” context, objective, subjective and psychoacoustics parameters for soundscape quality were measured in three spaces. As objective parameters, A-Weighted Equivalent Continuous Sound Levels (LeqA), Sound Pressure Levels" (SPL), Reverberation Time (RT), Speech Transmission Index (STI) were measured. For subjective parameters, sound recordings were taken with soundwalk method and noise annoyance surveys were applied simultaneously. A listening test and a survey were prepared to understand if spaces could be recognized/understood just by hearing. For psychoacoustics parameters, questionnaires were prepared and subjects were asked to fill in personal information and for each sound recording they listen, they were asked to fill in four open ended questions and choose from seventeen adjective pairs prepared with one to five likert scale. Ninety applicants participated in a listening test. Results showed that, acoustical measurements were higher than the permissible limits given in regulations. According to the noise annoyance survey results, enclosed spaces have the highest noise annoyance rating. Demographic factors such as age, gender, education level and space recognition did not showed any significant correlation. According to the listening test results, 70% of the subjects were able to determine spaces correctly as open, semi open or enclosed. Only 55% of the subjects were able to recognize the spaces. Soundmarks of the spaces show similarities. In open spaces subjects tended to choose adjectives such as "pleasant", "calming", "natural", "joyful"; while in enclosed spaces they tended to choose adjectives such as "unpleasant", "stressing", "artificial" , "empty".Bora, ZeynepM.S
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