scholarly journals The Accuracy of Predicted Acoustical Parameters in Ancient Open-Air Theatres: A Case Study in Syracusae

2018 ◽  
Vol 8 (8) ◽  
pp. 1393 ◽  
Author(s):  
Elena Bo ◽  
Louena Shtrepi ◽  
David Pelegrín Garcia ◽  
Giulio Barbato ◽  
Francesco Aletta ◽  
...  
Keyword(s):  
Modelling And Simulation ◽  
Just Noticeable Difference ◽  
Reverberation Time ◽  
Impulse Responses ◽  
Acoustical Parameters ◽  
Acoustic Parameters ◽  
Scattering Coefficients ◽  
Different Types ◽  
Good Agreement

Nowadays, ancient open-air theatres are often re-adapted as performance spaces for the additional historical value they can offer to the spectators’ experience. Therefore, there has been an increasing interest in the modelling and simulation of the acoustics of such spaces. These open-air performance facilities pose several methodological challenges to researchers and practitioners when it comes to precisely measure and predict acoustical parameters. Therefore this work investigates the accuracy of predicted acoustical parameters, that is, the Reverberation Time (T20), Clarity (C80) and Sound Strength (G), taking the ancient Syracusae open-air theatre in Italy as a case study. These parameters were derived from both measured and simulated Impulse Responses (IR). The accuracy of the acoustic parameters predicted with two different types of acoustic software, due to the input variability of the absorption and scattering coefficients, was assessed. All simulated and measured parameters were in good agreement, within the range of one “just noticeable difference” (JND), for the tested coefficient combinations.

scholarly journals The Effects of Adding Pyramidal and Convex Diffusers on Room Acoustic Parameters in a Small Non-Diffuse Room

Acoustics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 618-643
Author(s):  
Hassan Azad ◽  
Julie Meyer ◽  
Gary Siebein ◽  
Tapio Lokki
Keyword(s):  
Statistical Analysis ◽  
Large Scale ◽  
Reverberation Time ◽  
Impulse Responses ◽  
Acoustical Parameters ◽  
Acoustic Parameters ◽  
Acoustical Properties ◽  
Measurement Results ◽  
The Difference ◽  
Rectangular Room

This paper presents an investigation of the effects of relatively large-scale pyramidal and convex-shaped diffusers on the acoustical properties of a small non-diffuse rectangular room. Room impulse responses (RIRs) were measured in various room configurations to extract the early decay time (EDT), reverberation time (T20), early-to-late arriving sound ratio (C50), and clarity (C80). The difference between the parameters measured in the empty room were chosen to be the reference, and those measured in other room configurations was calculated. Statistical analysis of the measurement results supplements the investigation to determine whether the coverage and type of diffusers contribute significantly to the variation of the acoustical parameters. The results show that adding diffusers in the room generally decreases EDT as well as T20, and increases C50 as well as C80 for both diffuser types. The statistical analysis shows that the coverage of diffusers significantly contributes to the variation of the acoustical parameters in most conditions (octave band, diffuser type). The effect of the diffuser shape is only significant for some of the conditions (at 4 kHz, the number of diffusers). The data presented demonstrate that in a small non-diffuse room the reverberation can be controlled efficiently by redirecting the sound energy towards the most absorbing surfaces.

scholarly journals Logatome and Sentence Recognition Related to Acoustic Parameters of Enclosures

2017 ◽  
Vol 42 (3) ◽  
pp. 385-394
Author(s):  
Jedrzej Kocinski ◽  
Edward Ozimek
Keyword(s):  
Speech Recognition ◽  
Reverberation Time ◽  
Impulse Responses ◽  
Acoustic Parameters ◽  
Music School ◽  
Sentence Recognition ◽  
Speech Reception ◽  
Middle Range ◽  
Transmission Index ◽  
Speech Transmission

AbstractThe paper deals with relationship between speech recognition and objective parameters of enclosures. Six enclosures were chosen: a church, an assembly hall of a music school, two courtrooms of different volumes, a typical auditorium and a university concert hall. Dirac 4.1 software was used to record impulse responses (IRs) in the chosen measurement points of each enclosure. On this base, the following objective parameters of the enclosure were determined: Reverberation Time (RT), Early Decay Time (EDT), Weighted Clarity (C50) and Speech Transmission Index (STI). A convolution of the IRs with logatome tests and the Polish Sentence Test (PST) was made. Logatome recognition and speech reception threshold (SRT - i.e., SNR yielding 50% speech recognition) were evaluated and their dependence on the objective parameters were determined. Generally a linear relationship between logatome or SRT and RT or EDT was found. However, speech recognition was nonlinearly related (according to psychometric function) to STI values. The most sensitive range of the logatome and sentence recognition relative to STI changes corresponded to the middle range of STI values. Below and above this range, logatome and sentence recognition were much less dependent of STI changes.

The effects of different ceiling structures and plan typologies on acoustical conditions of historical mosques

2021 ◽  
Vol 263 (4) ◽  
pp. 2533-2543
Author(s):  
Fatma Yelkenci Sert ◽  
Özgül Yılmaz Karaman ◽  
Özgül Yilmaz Karaman
Keyword(s):  
Mathematical Modelling ◽  
Geometric Parameter ◽  
Speech Intelligibility ◽  
Acoustical Parameters ◽  
Acoustic Parameters ◽  
Building Type ◽  
Muslim People ◽  
Different Types ◽  
High Level ◽  
Acoustical Data

Mosque is a building type used by Muslim people consists of speech and music rituals. Good acoustical condition in mosques is an important issue to provide desired acoustical environment for prayers and Imams during different worship rituals. Prayers need to feel individuality in praying and the sense of unity in recitation of the Quran, hymns. Worship activities need a high level of speech intelligibility and to satisfy prayers in the spiritual aspects which make people feel closed to the God. In the context of study, six historical mosques in Turkey, with different types of cover structures and plan typologies, are designated as study areas. The present study contains two methods which the first one is collecting acoustical data by measurements and the second consists of mathematical modelling software program. The purpose of study to investigate effects of different plan typology and ceiling structures on acoustical characteristics in mosques with similar volume. Also, distribution of acoustical parameters and the suitability of the values obtained through acoustic simulations and measurements to the recommended values are aimed to be investigated. As a result of the investigations, it was concluded that the objective acoustic parameters of mosques changed according to the geometric parameter properties.

scholarly journals Low Cost Omnidirectional Sound Source Utilizing a Common Directional Loudspeaker for Impulse Response Measurements

2018 ◽  
Vol 8 (9) ◽  
pp. 1703 ◽  
Author(s):  
Nikolaos Papadakis ◽  
Georgios Stavroulakis
Keyword(s):  
Standard Deviation ◽  
Impulse Response ◽  
Sound Source ◽  
Mean Absolute Error ◽  
Low Cost ◽  
Absolute Error ◽  
Primary Method ◽  
Reverberation Time ◽  
Impulse Responses ◽  
Acoustic Parameters

Alternative low-cost sources (e.g., balloons, gun fires) are used for impulse response measurements when a dodecahedron speaker is not available. This study sets to explore the applicability of a method utilizing a common directional loudspeaker as a sound source. For this purpose measurements were performed in three spaces with three different common directional loudspeakers. Different placements of the loudspeakers were performed (twelve positions similar to the twelve positions of the faces of a dodecahedron speaker, different rotations of the loudspeakers for a total sum of twenty six and fourteen positions). The impulse responses obtained were added up creating a single impulse response for each case. Comparisons of the acoustic parameters measured with the proposed method and with a dodecahedron speaker are presented and suggest the expected mean absolute error and standard deviation for similar measurements. Reverberation time measurements show a mean absolute error of less than 0.08 s, as compared with measurements with a dodecahedron speaker. The proposed method can be the primary method for measuring impulse responses when a dodecahedron speaker is not available. Suggested improvements may lead to better omnidirectionality as compared with a dodecahedron loudspeaker, and set the method applicable to be utilized for auralization purposes.

scholarly journals A Study of Classroom Acoustics and Its Effects of Listeners’ Locations on Speech Intelligibility

1970 ◽  
Vol 7 (1) ◽  
pp. 64-71
Author(s):  
Chukiet Sodsri
Keyword(s):  
Linear Systems ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Noise Source ◽  
Reverberation Time ◽  
Impulse Responses ◽  
Acoustical Parameters ◽  
Classroom Acoustics ◽  
Common Process ◽  
Speech Clarity

Attending a class and listening to a lecture given by an instructor is a common process in Thailand education. Ability of learning is affected by the ability of hearing the instructors’ speech. Acoustical environments of the classroom, hence, can influence speech intelligibility. In this research, acoustical parameters and listeners’ locations in classrooms and their effects on the speech intelligibility were studied. By using an assumption of linear systems of the classrooms, the room reverberation, background noise, and other classroom acoustical factors can be implicated as impulse responses of the system. Maximum length sequence was used to identify the impulse responses at listeners’ locations in the classrooms. A clean speech, recorded in a semi-anechoic room, was convoluted with a series of the measured classrooms’ impulse responses to yield a set of simulated reverberant speeches that the listener at each location in the classes would have heard. A number of volunteers were invited to test an ability of understanding the speech. The experimental results showed that the reverberation and background noise at listeners’ locations severely affected the speech intelligibility. A classroom, that seemed to have a good averaged reverberation time, did not always yielded good speech clarity for all the locations in the class. In fact, for the classroom used in the study, the rear section of the class was poor for intelligibility and the back corner closed to a noise source was the worse location for speech hearing.

scholarly journals Acoustic Design of a Classical Concert Hall and Evaluation of its Acoustic Performance – A Case Study

2018 ◽  
Author(s):  
Kwangbok Jeong ◽  
Taehoon Hong ◽  
Sung Hoon Kim ◽  
Jimin Kim ◽  
Sangyoub Lee
Keyword(s):  
South Korea ◽  
Simulation Modeling ◽  
Decision Makers ◽  
Reverberation Time ◽  
Acoustic Parameters ◽  
Concert Hall ◽  
Acoustic Performance ◽  
Acoustic Design ◽  
Acoustic Simulation

This study aims at an acoustic design of the classical concert hall and evaluation of the acoustic performance. In terms of three acoustic parameters (i.e., reverberation time (RT), clarity (C80), and lateral fraction (LF)), this study performed acoustic simulation modeling and site measurement with the K Art Hall located in South Korea as a case study. First, in order to meet the acoustic performance of the K Art Hall (target RT: 1.4~1.7 seconds, target C80: -2dB or more +2dB or less, and target LF: 10~35%), the finish materials and shape of the room as an interior acoustic design were determined. Second, the average values of the RT, C80, and LF using the acoustic simulation modeling were estimated at 1.4 second, 1.2~1.6 dB, and 29%, respectively. Third, the average values of the RT, C80, and LF through site measuring were measured at 1.5~1.64 second, 0.07~1.31dB, and 22.22~31.37%, respectively. Thus, the results of both the acoustic simulation modeling and site measuring were analyzed so as to satisfy the target acoustic performance. The results of this study will help the decision-makers (i.e., owner, construction managers, etc.) to plan the classical concert hall in terms of the RT, C80, and LF.

Rule Invention in the Acquisition of Morphology Revisited

1988 ◽  
Vol 31 (3) ◽  
pp. 425-431 ◽  
Author(s):  
Stephen M. Camarata ◽  
Lisa Erwin
Keyword(s):  
Language Acquisition ◽  
Active Role ◽  
Acoustic Parameters ◽  
Impaired Child ◽  
Language Impaired ◽  
Intensity Parameters ◽  
Suprasegmental Features ◽  
Acoustic Analyses ◽  
Suprasegmental Cues

This paper presents a case study of a language-impaired child who signaled the distinction between English singular and plural using suprasegmental cues rather than the usual segmental form used within the parent language. Acoustic analyses performed within the first study in the paper revealed that the suprasegmental features used to maintain this distinction included various duration, fundamental frequency, and intensity parameters. Acoustic analyses Were also performed on a set of matched two- and four-item plural forms within a second study. The results of these analyses indicated that the same acoustic parameters were used to distinguish two-item plural forms from four-item plural forms. This case of linguistic creativity is offered as further evidence in support of the model of language acquisition that emphasizes the active role children take in the acquisition process. Additionally, the phonological, morphological, and psycholinguistic factors that may contribute to such rule invention are discussed.

Participatory Mapping in Browns Canyon National Monument, Colorado (USA)

2017 ◽  
Vol 1 (1) ◽  
pp. 1-16
Author(s):  
John Harner ◽  
Lee Cerveny ◽  
Rebecca Gronewold
Keyword(s):  
Land Management ◽  
Planning Process ◽  
Management Plan ◽  
Bureau Of Land Management ◽  
National Monument ◽  
Resource Managers ◽  
Different Types ◽  
Us Forest Service ◽  
Natural Resource Managers

Natural resource managers need up-to-date information about how people interact with public lands and the meanings these places hold for use in planning and decision-making. This case study explains the use of public participatory Geographic Information System (GIS) to generate and analyze spatial patterns of the uses and values people hold for the Browns Canyon National Monument in Colorado. Participants drew on maps and answered questions at both live community meetings and online sessions to develop a series of maps showing detailed responses to different types of resource uses and landscape values. Results can be disaggregated by interaction types, different meaningful values, respondent characteristics, seasonality, or frequency of visit. The study was a test for the Bureau of Land Management and US Forest Service, who jointly manage the monument as they prepare their land management plan. If the information generated is as helpful throughout the entire planning process as initial responses seem, this protocol could become a component of the Bureau’s planning tool kit.

THE INFLUENCE OF ROOM ACOUSTIC PARAMETERS ON THE PERCEPTION OF ROOM CHARACTERISTICS

Akustika ◽  
2020 ◽  
pp. 28
Author(s):  
Alicja Jasińska ◽  
Maurycy Kin
Keyword(s):  
Standard Deviation ◽  
Subjective Evaluation ◽  
Strength Parameter ◽  
Acoustic Parameters ◽  
Sound Sources ◽  
Different Types

The article presents the possibility of identification of rooms on the basis of binaural perception. Results of subjective evaluation were compared with the values of sound strength, G. A previously unknown sound term was introduced: the strength of spatial impression as the inverse of standard deviation of the results obtained. It turned out that the results presenting the sound strength parameter can be correlated with the subjective evaluation of the spatial impression, which is the size of the room. It can be helpful in the process of room identification, probably due to the reverberation impression in the room. Authors plan to continue the study with more rooms and different types of sound sources.

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