scholarly journals Improved Room Acoustics Quality in Meeting Rooms: Investigation on the Optimal Configurations of Sound-Absorptive and Sound-Diffusive Panels

Acoustics ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 451-473 ◽  
Author(s):  
Laura Labia ◽  
Louena Shtrepi ◽  
Arianna Astolfi
Keyword(s):  
Optimal Number ◽  
Optimal Placement ◽  
Room Acoustics ◽  
Acoustic Measurements ◽  
Transmission Index ◽  
Speech Transmission ◽  
Acoustic Quality ◽  
Optimal Configurations ◽  
And Diffusion

This work deals with the improvement of the room acoustic quality of two medium sized meeting rooms through the investigation of the optimal placement of absorption and diffusive panels on the walls and ceiling. Acoustic measurements have been carried out in the existing untreated rooms with ODEON 13 room acoustics measurement and prediction software, and the Adobe Audition plugins Aurora. Simulations of different combinations of sound absorption and diffusion treatments have been carried out with the updated version of the software, ODEON 15. The panels were positioned in the meeting rooms following the guidelines of the DIN 18041 standard and the scientific literature. The results advise the application of absorptive materials on the ceiling or around the borders, creating a reflective middle area, and on the upper part of one the lateral walls, including the rear wall. Configurations with diffusers do not generally bring significant improvements. The Speech Transmission Index (STI) is a less sensitive parameter for the different acoustic scenarios, compared to Reverberation Time (T) and Clarity (C50). The research also outlined a design workflow, useful to successfully design meeting rooms and rooms for speech in general, which allows to determine the optimal number and location of acoustic panels and to minimize the costs.

scholarly journals The Assessment of Acoustical Characteristics for Recent Mosque Buildings in Erbil City of Iraq

2021 ◽  
Vol 9 (1) ◽  
pp. 51-66
Author(s):  
Dawa A. A. Masih ◽  
Nawzad K. Jalal ◽  
Manar N. A. Mohammed ◽  
Sulaiman A. Mustafa
Keyword(s):  
Speech Intelligibility ◽  
Sound Quality ◽  
Design Guidelines ◽  
Room Acoustics ◽  
Quality Level ◽  
Transmission Index ◽  
Speech Transmission ◽  
Acoustic Quality ◽  
And Performance

The study of mosque acoustics, concerning acoustical features, sound quality for speech intelligibility, and additional practical acoustic criteria, is commonly overlooked. Acoustic quality is vital to the fundamental use of mosques, in terms of contributing toward prayers and worshippers’ appreciation. This paper undertakes a comparative analysis of the acoustic quality level and the acoustical characteristics for two modern mosque buildings constructed in Erbil city. This work investigates and examines the acoustical quality and performance of these two mosques and their prayer halls through room simulation using ODEON Room Acoustics Software, to assess the degree of speech intelligibility according to acoustic criteria relative to the spatial requirements and design guidelines. The sound pressure level and other room-acoustic indicators, such as reverberation time (T30), early decay time, and speech transmission index, are tested. The outcomes demonstrate the quality of acoustics in the investigated mosques during semi-occupied and fully-occupied circumstances. The results specify that the sound quality within the both mosques is displeasing as the loudspeakers were off.

scholarly journals Comparison of Two Types of Combined Measures, STI and U50, for Predicting Speech Intelligibility in Classrooms

2017 ◽  
Vol 42 (3) ◽  
pp. 527-532 ◽  
Author(s):  
Young-Ji Cho
Keyword(s):  
Speech Intelligibility ◽  
Room Acoustics ◽  
Speech Communication ◽  
Modulation Transfer ◽  
Acoustic Measurements ◽  
Transmission Index ◽  
Speech Transmission ◽  
The Mean ◽  
University Classrooms ◽  
Made In

AbstractThe present study reports on the speech intelligibility as measured by speech transmission index (STI) and useful-to-detrimental sound ratios (U50) in university classrooms. Acoustic measurements were made in 12 quietly occupied university classrooms. The measured impulse responses of the classrooms were used to determine the modulation transfer function, m(F), for the STI calculation according to IEC 60268-16. U50values were determined from both signal-to-noise ratios (SNR) and C50values. The mean STI and frequency-weighted U50values for the 12 occupied classrooms were strongly linearly related. The results showed that classrooms with U50values of about +0.5 dB correspond to STI values of 0.60, indicating ‘good’ acoustical conditions for speech intelligibility. The results illustrate that the U50measure can be a more practically useful means of assessing and understanding room acoustics conditions for real speech communication in active classrooms.

scholarly journals Environmental Acoustic Comfort in the Built Environment

2021 ◽  
Vol 9 (71) ◽  
Author(s):  
Margret Sibylle Engel ◽  
Júlio Otávio Herrmann ◽  
Paulo Henrique Trombetta Zannin
Keyword(s):  
Teaching And Learning ◽  
Physical Structure ◽  
Sharp Drop ◽  
Speech Transmission ◽  
Acoustic Quality ◽  
Teachers And Students ◽  
Acoustic Comfort ◽  
The 1960S ◽  
Acoustic Conditions

  The acoustic quality of classrooms has a strong influence on the teaching and learning process. This interference assessed using the impulsive technique to measure the rate of speech transmission (STI), reverberation time (RT) and sound definition (D50). These are the most relevant acoustic descriptors in the assessment of classrooms, where verbal exposure is the means of communication between teachers and students. The evaluation took place in two buildings of the Federal University of Paraná (UFPR), built in the 1960s and another in 2016. The measured values ​​of STI, provided in the classrooms' actual acoustic conditions, were used as an adjustment parameter for simulations made with the software ODEON. After carrying out the measurements and simulations, the dimensioning of improvements was possible. The acoustic simulations presented suggestions to qualify the quality of the classrooms' acoustic comfort, ensuring that teaching and learning to do not suffer losses due to the physical structure of the classrooms. The measured values ​​of STI, RT and D50 show that, in the old building, except for a single classroom that preserves the original ceiling that had a high sound absorption coefficient, it has reasonable values, below the ideal for classrooms, according to the IEC 60268-16 (2011) standard. The investigation showed that the rooms with a roof replaced by a PVC covering had a sharp drop in acoustic quality. The newest building has classrooms with proper acoustic comfort conditions.

scholarly journals Relationships between Subjective and Objective Acoustical Measures in Churches

1997 ◽  
Vol 4 (1) ◽  
pp. 1-20 ◽  
Author(s):  
António P.O. Carvalho ◽  
António E.J. Morgado ◽  
Luís Henrique
Keyword(s):  
Correlation Coefficients ◽  
Field Measurements ◽  
Room Acoustics ◽  
Significant Relationships ◽  
Architectural Features ◽  
Live Music ◽  
Acoustic Quality ◽  
Catholic Churches ◽  
Made In

This study reports on subjective and objective acoustical field measurements made in a survey of 36 Catholic churches in Portugal built in the last 14 centuries. Monaural acoustical measurements (RT, EDT. C80, D50, TS and L) were taken at several source/receiver locations in each church and a group of college students was asked to judge the subjective quality of music. The listeners in each church evaluated live music performances at similar locations in each room. Evaluation sheets were used to record the listeners' overall impressions of room acoustic quality and also Loudness, Reverberance. Intimacy. Envelopment. Directionality, Balance, Clarity, Echoes and Background Noise. This paper concentrates on the relationships of the subjective parameters with the objective room acoustics measures and with the architectural features of the churches. Correlation analyses and statistical modeling identified significant relationships among the measures. For instance, linear correlation coefficients (| R|) of 0.8–0.9 were found for the relationships: Reverberance/RT and Clarity/C80; the maximum | R| found was 0.93 for Echoes/RT. Regarding architectural features the maximum | R | found was 0.87 between Intimacy and Total Volume.

The acoustics of ancient catacombs in Southern Italy

2020 ◽  
pp. 1351010X2096757 ◽  
Author(s):  
Giuseppe Ciaburro ◽  
Umberto Berardi ◽  
Gino Iannace ◽  
Amelia Trematerra ◽  
Virginia Puyana-Romero
Keyword(s):  
Roman Empire ◽  
Sound Source ◽  
Southern Italy ◽  
Reverberation Time ◽  
Acoustic Measurements ◽  
Acoustic Characteristics ◽  
Christian Religion ◽  
Renaissance Period ◽  
Transmission Index ◽  
Speech Transmission

The catacombs, burial sites for early Christians, were constructed during the Roman Empire until the Christian religion was recognized in 313 AD. The catacombs were cementeries, which were organized according to precise rules and were dug into the ground on several levels, to occupy as little space as possible. The catacombs became places of worship as martyrs were buried in them. The catacombs were then abandoned with the barbarian invasions and the consequent construction of churches inside cities. The catacombs were rediscovered during the Renaissance period and became a place of renewed worship. In the present work, the acoustic characteristics of the catacombs of San Callisto in Rome, San Gennaro in Naples, and Vigna Cassia in Syracuse are discussed. The three selected catacombs differ by type of excavation and geometry. In particular, the catacombs of San Callisto are made of narrow corridors and small rooms; the catacombs of San Gennaro consist of large rooms with niches; the catacombs of Vigna Cassia are partly excavated in the tuff and partially occupy a disused aqueduct. The acoustic measurements were performed using an impulsive sound source. The description of the acoustic characteristics focuses on the reverberation time and the Speech Transmission Index. The results show that the reverberation time was always shorter than 1 second, confirming the reduced reverberation of these environments. Finally, the speech listening characteristics are particularly good, ensuring the suitable conditions for the prayer in these spaces.

scholarly journals An Assessment of Room Acoustics Performance of Baiturrahman Grand Mosque

Elkawnie ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 24
Author(s):  
Laina Hilma Sari ◽  
Zulfian Zulfian
Keyword(s):  
Architectural Design ◽  
Room Acoustics ◽  
Primary Data ◽  
Concrete Wall ◽  
Important Place ◽  
Transmission Index ◽  
Speech Transmission ◽  
History Of ◽  
Heavy Construction ◽  
Banda Aceh

Abstract : Acoustical design as part of the audio comfort influences the architectural design strategy of a mosque significantly. As belonging to the speech room criteria, a mosque should meet some acoustic room requirements to deliver the solemnness to the worshipper during the prayer. Concerning this, the study aims to assess the indoor acoustics performance of Baiturrahman Grand Mosque, Banda Aceh. Baiturrahman grand mosque is an important place of worship for Acehnese and becoming a landmark of Banda Aceh City. The mosque which contains a lot of history of Aceh was built in heavy construction, i.e. concrete wall, marble coated floor, and concrete dome ceiling. Due to its significance, the room acoustics of the mosque as the primary design considerations in a speech room type is evaluated. The acoustics parameters estimated are Noise Criteria (NC), Sound Pressure Level (SPL), Reverberation Time (RT), and Rapid Speech Transmission Index (RASTI). The background noise was recorded for delivering the noise criteria and being the primary data carried out in the acoustic simulation. The study utilised CATT-Acoustic v7.2 software for simulating predicting SPL, RT, and RASTI.Abstrak : Desain akustik merupakan bagian dari parameter audio yang mempengaruhi desain arsitektur masjid secara signifikan. Masjid termasuk dalam kategori speech room yang harus memenuhi beberapa persyaratan akustik ruang untuk dapat menghadirkan kekhusyukan kepada jamaah selama sholat. Penelitian ini bertujuan untuk menilai kinerja akustik dalam ruangan Masjid Raya Baiturrahman, Banda Aceh. Masjid Raya Baiturrahman adalah tempat ibadah yang penting bagi orang Aceh dan menjadi simbol Kota Banda Aceh. Masjid yang memuat banyak sejarah Aceh ini terbuat dari dinding beton, lantai berlapis marmer, dan langit-langit kubah beton. Pada studi ini, parameter akustik ruang yang dievaluasi adalah Kriteria Kebisingan (NC), Tingkat Tekanan Suara (SPL), Waktu Gema (RT), dan Indeks Transmisi kecepatan Bicara (RASTI). Kebisingan latar belakang direkam untuk memberikan kriteria kebisingan dan menjadi data primer yang dilakukan dalam simulasi akustik. Studi ini menggunakan perangkat lunak CATT-Acoustic v7.2 untuk mensimulasikan prediksi SPL, RT, dan RASTI.

scholarly journals Acoustic quality assessment in a classroom through simulations and measurements

2021 ◽  
Vol 9 (72) ◽  
Author(s):  
Eriberto Oliveira do Nascimento ◽  
Paulo Henrique Trombetta Zannin
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Reverberation Time ◽  
Vocal Health ◽  
Quality Requirements ◽  
Transmission Index ◽  
Speech Transmission ◽  
Acoustic Quality ◽  
Acoustic Comfort ◽  
Minimum Requirements

The acoustic quality in a classroom directly impacts the educational relationship between the student and the teacher, reducing speech intelligibility. In addition, inadequate acoustic comfort burdens the vocal health of teachers. This study evaluated a classroom at the Federal University of Paraná, Campus Centro Politécnico, to verify its acoustic quality. The measurements of the acoustics descriptors: Reverberation Time (RT), Definition (D50), Central Time (Ts), Early Decay Time (EDT) were performed according to the ISO 3382-2 standard, concerning Noise Curves (NC) and Background Noise (BGN) these were evaluated by the  NBR 10152 and S12.2 standards. The Speech Transmission Index (STI) was measured according to IEC 60268-16 and evaluated according to ISO 9921. The useful-detrimental ratio (U50) and the other descriptors were simulated in the ODEON software version 11. Thus, the results showed that the evaluated room did not meet the minimum requirements in terms of acoustic quality, for the descriptors RT, STI, Ts, D50, RF, and NC. Simultaneously, the RT and STI were also outside the limits established by the German and Finnish standards. Therefore, it is concluded that the evaluated classroom did not reach the minimum acoustic quality requirements.

scholarly journals A Study of the Acoustics and Speech Intelligibility Quality of Mosques in Malaysia

2014 ◽  
Vol 564 ◽  
pp. 129-134
Author(s):  
Abdul Hakim Abdullah ◽  
Zamir A. Zulkefli
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Prediction Models ◽  
Signal To Noise Ratio ◽  
Distribution Patterns ◽  
Speech Quality ◽  
Transmission Index ◽  
Speech Transmission ◽  
Rapid Transmission

This study presents the assessment of the quality of speech intelligibility of two Malaysian mosques and the results are used to develop a set of general acoustical guidelines to be used in the design of a mosque. Two mosques were selected for the research: Masjid UPM and the Masjid Jamek. The objective of the research is to enable the comparison of the acoustics and speech intelligibility between the mosques as function of the size, volume, occupancy and other parameters of the main prayer hall on the acoustic and speech intelligibility of the respective mosques. The reverberation time (RT60), speech level (SL), background noise (BN), signal-to-noise ratio (S/N ratio) were determined and are used to develop the speech transmission index (STI) and rapid transmission index (RASTI) prediction models for both mosques. It was observed from the results that the RT60, STI and RASTI values shows better performance over number of occupancy for both mosques. Furthermore, the BN and SL results were visualized using the spatial distribution patterns (SDP) of the main hall. The results of the analysis show that the overall acoustic and speech quality of Masjid Jamek is better when compared to the overall acoustic and speech quality of Masjid UPM. These results are then used to develop a set of design recommendations to ensure adequate speech intelligibility quality a mosque.

scholarly journals STI direct test method based on wavelet transform to extract envelope

2021 ◽  
Vol 2132 (1) ◽  
pp. 012029
Author(s):  
Wenxin Wang ◽  
Ranran Zhu ◽  
Hongliang Zhao
Keyword(s):  
Wavelet Transform ◽  
Test Method ◽  
Direct Test ◽  
Pink Noise ◽  
Signal Envelope ◽  
Voice Signal ◽  
Important Index ◽  
Transmission Index ◽  
Speech Transmission

Abstract Speech transmission index (STI for short) is an important index to evaluate the quality of speech transmission of the room, it can better reflect the degree of voice signal affected by room reverberation and noise in the transmission process.This paper presents an algorithm for directly measuring STI index, white noise is filtered by Paul Kellet filter to generate pink noise, the signal envelope is extracted by wavelet transform, which improves the extraction accuracy of signal envelope and makes the measurement of STI index more accurate.

scholarly journals Prediction and Evaluation of Emergency Broadcasting Sound and Speech Intelligibility for Safety Zones in High-rise Buildings

2020 ◽  
Vol 34 (6) ◽  
pp. 37-43
Author(s):  
Jeong-Ho Jeong
Keyword(s):  
Fire Safety ◽  
Speech Intelligibility ◽  
Detection System ◽  
Simulation Method ◽  
Room Acoustics ◽  
Radio Communication ◽  
Safety Zone ◽  
High Rise ◽  
Transmission Index ◽  
Speech Transmission

As construction of high-rise buildings is increasing, the installation of a fire safety zone for the safe evacuation of residents has become mandatory. Even for building complexes with an underground connection between 30 and 49 stories, a fire safety zone must be installed when the residential density exceeds 1.5 people per square meter. In the fire safety zone, an automatic fire detection system and a system to assist radio communication must be installed. In addition, an emergency broadcasting system must be installed to announce the fire situation and to guide the safe evacuation of the residents. The fire safety zone was constructed with non-combustible material to minimize flames or smoke and was furnished to maintain a very low fire load. However, non-combustible materials have very low sound absorption characteristics; therefore, they usually reflect the sound energy into the spaces. In spaces consisting of sound reflective materials, the emergency broadcasting sounds reverberated, making it difficult to understand the meaning of the broadcasted sound. In this study, the room acoustics characteristics for fire safety zones in a high-rise building, represented as reverberation time and speech transmission index, were predicted using a certified room acoustics simulation method and evaluation of speech intelligibility. As a result of predicting the acoustic characteristics of the safety zone, it was found that the space had quite long reverberation and speech intelligibility was low, making it difficult to clearly transmit the emergency broadcast sound. When a safety zone was set up in a part of the machinery room, it was confirmed that it was difficult to clearly transmit the emergency broadcast sound, even when the background noise level was louder than 70 dB(A). To deliver a clear emergency broadcast sound in the safety zone, it is necessary to use inorganic sound-absorbing materials and to properly block noise in the machine room. In addition, it is necessary to establish guidelines for regulation of the speech transmission index for emergency broadcasting systems.

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