Case Study: Acoustic Design of a Restored Theatre in Thessaloniki

2000 ◽  
Vol 7 (2) ◽  
pp. 137-150
Author(s):  
N. P. Tsinikas
Keyword(s):  
Background Noise ◽  
Lateral Wall ◽  
Reverberation Time ◽  
Noise Levels ◽  
Acoustic Design ◽  
Design Changes ◽  
Wire Frame ◽  
Measurement Results ◽  
Side Walls

This paper discusses the acoustics of a restored theatre in Thessaloniki, Greece. The paper presents the acoustic design principles, discusses the employment of these principles and concludes with an assessment of the success of the design. The acoustic design changes included improvement of direct sound, provision of ceiling and walls reflections, positioning of diffusers, optimising reverberation time and minimising background noise levels. Steeper seating rakes were constructed in the stalls, boxes and balconies. Curved ceiling reflectors were positioned in a new wire frame false ceiling. Lateral wall reflectors were introduced, as were curved side walls near the stage to act as diffusers. Diffusers were positioned in the rear walls and in balcony fronts. Reverberation times were predicted, measured and compared with earlier data, based on the change of volume, the number and design of seats and the volume per seat ratio. Finally, noise level measurements were obtained in most of the spaces in the theatre. Assessment of the success of the design is based on measurement results and on the subjective acceptance by theatre goers.

scholarly journals Acoustic Environment and Noise Exposure in Fitness Halls

2020 ◽  
Vol 10 (18) ◽  
pp. 6349
Author(s):  
Omaimah Ali Al-Arja
Keyword(s):  
Noise Level ◽  
Noise Exposure ◽  
Subjective Rating ◽  
Reverberation Time ◽  
Noise Levels ◽  
Acoustic Environment ◽  
Exposure Limit ◽  
Raising Awareness ◽  
Measurement Results ◽  
T Values

People seek health and leisure in gyms and fitness halls. In this study, interior acoustics including reverberation time (T) and activity noise levels were studied in 20 indoor sports and gymnasium (IS & G) halls in Amman, Jordan. Interviews and questionnaires were also applied to assess the subjective comfort levels of the acoustic environment in these IS & G halls. The measured values were correlated with the subjective evaluations. The range of measured T values was 1.09–5.38 s. The activity noise level, which was measured with LA,eq over 50 min of activity, ranged between 80.0 and 110.0 dB(A). The average personal noise exposure for instructors was 92.6 dB(A), ranging from 81.0 to 108.0 dB(A), whereas 90% of the measurement results were above the occupational exposure limit (OEL) of 85.0 dB(A), and 40% of instructors were potentially exposed to excessive noise levels. The subjective rating of listening conditions correlated significantly with the reverberation time rather than noise level (p < 0.01). In conclusion, the results from this study show that noise levels generated in the studied IS & G halls present a possible workplace noise hazard. Raising awareness of the risk of hearing problems among instructors working in IS & G halls is highly recommended.

scholarly journals Helicopter Inside Cabin Acoustic Evaluation: A Case Study—IAR PUMA 330

2021 ◽  
Vol 18 (18) ◽  
pp. 9716
Author(s):  
Marius Deaconu ◽  
Grigore Cican ◽  
Adina-Cristina Toma ◽  
Luminița Ioana Drăgășanu
Keyword(s):  
Noise Exposure ◽  
Flight Test ◽  
Noise Levels ◽  
Noise Sources ◽  
High Noise ◽  
Measurement Campaign ◽  
Measurement Results ◽  
Noise Assessment ◽  
Acoustic Evaluation

This paper presents an inside-cabin acoustic evaluation of the IAR PUMA 330 helicopter, manufactured by IAR S.A. Brasov. In this study, based on the acoustic assessment inside the helicopter, areas with high noise levels are identified. In this regard, several tests were carried out in accordance with the ISO 5129 standard. In the first stage of the assessment, a measurement campaign was performed to identify the acoustic leaks from the outside noise sources propagating inside the cabin (in the door area) and the acoustic attenuation of the helicopter structure. These tests were performed on the factory runway, with the helicopter in parked position (ground tests). During the ground tests, the helicopter engines were turned off. The tests consisted of placing two loudspeakers directed towards the helicopter door and generating pink noise. Inside the helicopter, the entire door frame opening was scanned with an intensity probe to identify acoustic leaks areas. The second assessment stage was to determine the areas of the cabin with the highest levels of noise. Within the measurement campaign, 16 microphones were placed inside the cabin, at the level of the passengers’ heads, arranged in seven zones. The tests were carried out with the helicopter engines started, staying at fixed point above the ground (hovering), and then a flight test, in which all the maneuvers necessary for the use of the helicopter were performed (in-flight tests). Based on the measurement results, it was possible to highlight the noise spectral components in each of the seven areas. The noise assessment revealed high noise levels inside the cabin, having as main noise sources the transmission gear and the door area, leading to the need for reducing the noise exposure for passengers and crew, thus the need to reduce noise levels inside the helicopter.

Effects of Classroom Noise on Students and Teachers in Greece

2003 ◽  
Vol 96 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Dimitris Skarlatos ◽  
Manolis Manatakis
Keyword(s):  
High School ◽  
Background Noise ◽  
Reverberation Time ◽  
Noise Levels ◽  
High Background ◽  
High Noise ◽  
Significant Percentage ◽  
Time Period ◽  
High Background Noise

Measurements inside 32 occupied high-school classrooms during the courses showed that the measured long-term equivalent noise levels are high. A significant percentage of students and teachers found these levels unacceptable. The observed noise levels depend on the time period of the course, the age, and the number of the students in each classroom. The large reverberation time and the high background noise are responsible for the measured high noise level.

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.

Exploring Effective Change Propagation in a Product Family Design

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Inayat Ullah ◽  
Dunbing Tang ◽  
Qi Wang ◽  
Leilei Yin
Keyword(s):  
Product Family ◽  
Design Structure Matrix ◽  
Change Propagation ◽  
Effective Change ◽  
Design Structure ◽  
Design Changes ◽  
Requirements Change ◽  
Change Impact ◽  
Design Requirements

Product family (PF) design is a widely used strategy in the industry, as it allows meeting diverse design requirements. Change propagation in any PF is difficult to predict. Consequently, while numerous design change management methodologies presently exist, their application is restricted to a single artifact. This issue is overcome in the present study. The proposed framework explores effective change propagation paths (CPPs) by considering the risks associated with design changes in the PF with the aim of minimizing the overall redesign cost. The propagated risk, which would result in rework, is quantified in terms of change impact and propagation likelihood. Moreover, a design structure matrix (DSM) based mathematical model and an algorithm for its implementation are proposed to investigate the change propagation across the PF. Finally, to demonstrate their effectiveness, a PF of electric kettles is examined in a case study. The study findings confirm that the proposed technique is appropriate for evaluating different CPPs in PF.

Speech Intelligibility Parameters for Evaluating the Perception of Background Noise in Open-Plan Office Users: A Case Study

2021 ◽  
Author(s):  
María Serrano Ruiz
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Acoustic Analysis ◽  
Physical Factors ◽  
Space Design ◽  
Transmission Index ◽  
Open Plan ◽  
Design Characteristics

This document presents a case study of acoustic analysis in an open-plan office. Since Mexico does not have a standard for evaluating acoustic conditions in offices, it is relevant to compare different acoustic evaluation methods used for open-plan offices. According to several studies, one of the main acoustic characteristics for open-plan office spaces is speech intelligibility. Therefore, the purpose of this document is to compare psychoacoustic parameters to evaluate speech intelligibility in open-plan offices. We analyzed physical factors as reverberation and speech clarity in different office points, as well as semantic factors based on subjective methods with standardized values of the quality of speech intelligibility. The study was carried out under real open-plan office conditions in a library in a university in northern Mexico. The study factors of interest were type of sound, sound source, and location of the listener, with Reverberation Time (RT), Speech Transmission Index (STI) and Loss of consonant articulation (%ALCons) as the measures of impact on intelligibility. This case study provides additional evidence of the relationship between intelligibility and the position of sound sources; also, it was noted that location of listeners influenced analyzed intelligibility parameters. On the other hand, this case study offers information concerning to use psychoacoustic parameters for subjective classification of quality of the speech intelligibility to evaluate how is background noise perceived in open-plan office users. However, it is noteworthy that this study represents a single office with its own interior and space design characteristics.

The Canterbury Child's Aid: A Binaural Spatial Sensor for Research with Blind Children

1979 ◽  
Vol 73 (5) ◽  
pp. 179-184
Author(s):  
E. R. Strelow ◽  
J. T. Boys
Keyword(s):  
Future Development ◽  
Background Noise ◽  
Field Of View ◽  
Basic Operation ◽  
Noise Levels ◽  
Design Features ◽  
Blind Children ◽  
Automatic Level

A binaural sensory aid for research with blind children is described along with the rationale for its design features. The basic operation of this form of aid is described in detail with particular reference to those features that control the sensing parameters of range, direction and field of view. A novel automatic level controller which ensures that device sounds remain audible but not excessively loud, in spite of changes in background noise levels, is also described. The likely future development of these forms of sonic aids is discussed.

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