Mapping speech transmission index (STI) and background noise in university classrooms

2017 ◽  
Vol 141 (5) ◽  
pp. 3481-3481
Author(s):  
Andrew Hulva ◽  
Michael Ermann ◽  
Jeffrey Rynes ◽  
Randall J. Rehfuss ◽  
Aaron Kanapesky ◽  
...  
Keyword(s):  
Background Noise ◽  
Transmission Index ◽  
Speech Transmission ◽  
University Classrooms

Further Validation of the Speech Transmission Index (STI)

1987 ◽  
Vol 30 (3) ◽  
pp. 403-410 ◽  
Author(s):  
Larry E. Humes ◽  
Stephen Boney ◽  
Faith Loven
Keyword(s):  
Speech Recognition ◽  
Background Noise ◽  
Recognition Task ◽  
Sound Field ◽  
Normal Hearing ◽  
Noise Levels ◽  
Transmission Index ◽  
Speech Transmission ◽  
Binaural Listening ◽  
Prospective Analyses

The present article further evaluates the accuracy of speech-recognition predictions made according to two forms of the Speech Transmission Index (STI) for normal-hearing listeners. The first portion of this article describes the application of the modified Speech Transmission Index (mSTI) to an extensive set of speech-recognition data. Performance of normal-hearing listeners on a nonsense-syllable recognition task in 216 conditions involving different speech levels, background noise levels, reverberation times and filter passbands was found to be monotonically related to the mSTI. The second portion of this article describes a retrospective and prospective analysis of an extended sound-field version of the STI, referred to here as STI x . This extended STI considers many of the variables relevant to sound-field speech recognition, some of which are not incorporated in the mSTI. These variables include: (a) reverberation time; (b) speech level; (e) noise level; (d) talker-to-listener distance; (e) directivity of the speech source; and (f) directivity of the listener (eg., monaural vs. binaural listening). For both the retrospective and prospective analyses, speech-recognition was found to vary monotonically with STI x .

Aircraft interior acoustics - background noise contamination

2021 ◽  
Vol 263 (5) ◽  
pp. 1606-1619
Author(s):  
Ramana Kappagantu ◽  
Manuel Etchessahar ◽  
Edgar Matas ◽  
Koen Vansant
Keyword(s):  
High Frequency ◽  
Background Noise ◽  
Noise Source ◽  
Operating Conditions ◽  
Low Frequencies ◽  
Acoustic Design ◽  
Points Of Interest ◽  
Transmission Index ◽  
Speech Transmission ◽  
Noise Contamination

Aircraft interior noise is an important factor to be considered for cabin comfort. In a cruising condition this noise source is mostly broadband in nature and is coming from the exterior, primarily the turbulent boundary layer (TBL) of the flow around the moving aircraft. Capturing this noise to a high frequency is critical for designing the sound packaging. Also, this becomes important in the design of public announcement (PA) system for the aircraft cabin, i.e. the correct placement of speakers. One of the metrics used for this acoustic design is speech transmission index. Deterministic techniques like finite or boundary element techniques for low frequencies and ray tracing method to reach higher frequencies are better suited for getting the narrow band responses. On the other hand, to characterize the background noise due to the TBL loads, statistical energy analysis (SEA) route is pursued. In this paper the authors combine different techniques to capture the background noise and use them with PA sources and eventually capture the sound perceived at points of interest. The articulation metrics are compared for different operating conditions of the aircraft. In the presentation attempts will be made to play the auralized sounds.

Impact of Partition types on Architecture design studios acoustical environment

2021 ◽  
Vol 263 (1) ◽  
pp. 5847-5857
Author(s):  
Hany Hossam Eldien ◽  
Umaru Bongwirnso
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Architecture Design ◽  
Front Side ◽  
Open Spaces ◽  
Transmission Index ◽  
Speech Transmission ◽  
Open Plan ◽  
High Level ◽  
Two Sides

Working in Architecture design studios environment requires various activities. Interaction, communication and meetings could affect the speech intelligibility and the speech privacy conditions. Students Areas with a more silent environment are needed with a minimized level of distraction from surrounding activities, while teamwork and discussion areas with a high level of interaction need a good speech intelligibility. One of the more important elements which can improve the open spaces acoustical conditions is the partitions between workstations.The main purpose of this work is to evaluate the acoustical performance of four partitions types in open plan offices; 1.10m two sides partition height, 1,50m front side partitions, 1,50m one side partitions and 1.50 two sides partitions. This Study was conducted in the College of Architecture, Imam Abdulrhman Bin Faisal University, KSA. Based on ISO 3382-3, Speech Transmission Index, STI in the nearest workstation, Distraction distance rD, privacy distance rP, A-weighted background noise level L,A,B and A-weighted SPL of speech at 4 metres L,A,S,4m have been measured. It was found that the best results can be obtained by 1.50m front side and 1.50m two sides partitions.

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 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 Speech transmission index variation due to ventilating and air-conditioning system in university classrooms

2016 ◽  
Author(s):  
Hugo C. Longoni ◽  
Sebastian P. Ferreyra ◽  
Gabriel A. Cravero ◽  
Facundo López ◽  
Manuel F. Parada ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Air Conditioning System ◽  
Transmission Index ◽  
Speech Transmission ◽  
Index Variation ◽  
University Classrooms

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.

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