scholarly journals An Experimental Study of Acoustic Comfort in Open Space Banks Based on Speech Intelligibility and Noise Annoyance Measures

2017 ◽  
Vol 42 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Rostam Golmohammadi ◽  
Mohsen Aliabadi ◽  
Trifah Nezami
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Open Space ◽  
Irrelevant Speech ◽  
Acoustic Properties ◽  
Noise Levels ◽  
Noise Annoyance ◽  
Transmission Index ◽  
Acoustic Comfort ◽  
Bank Employees

Abstract Tasks requiring intensive concentration are more vulnerable to noise than routine tasks. Due to the high mental workload of bank employees, this study aimed to evaluate acoustic comfort in open-space banks based on speech intelligibility and noise annoyance metrics. Acoustic metrics including preferred noise criterion (PNC), speech transmission index (STI), and signal to noise ratio (SNR) were measured in seventeen banks (located in Hamadan, a western province of Iran). For subjective noise annoyance assessments, 100-point noise annoyance scales were completed by bank employees during activities. Based on STI (0.56±0.09) and SNR (20.5±8.2 dB) values, it was found that speech intelligibilities in the workstations of banks were higher than the satisfactory level. However, PNC values in bank spaces were 48.2±5.5 dB, which is higher than the recommended limit value for public spaces. In this regard, 95% of the employees are annoyed by background noise levels. The results show irrelevant speech is the main source of subjective noise annoyance among employees. Loss of concentration is the main consequence of background noise levels for employees. The results confirmed that acoustic properties of bank spaces provide enough speech intelligibility, while staff’s noise annoyance is not acceptable. It can be concluded that due to proximity of workstations in open-space banks, access to very short distraction distance is necessary. Therefore, increasing speech privacy can be prioritised to speech intelligibility. It is recommended that current desk screens are redesigned in order to reduce irrelevant speech between nearby workstations. Staff’s training about acoustic comfort can also manage irrelevant speech characteristics during work time.

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.

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.

Challenging listening environments in higher education: an analysis of academic classroom acoustics

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kirsten van den Heuij ◽  
Theo Goverts ◽  
Karin Neijenhuis ◽  
Martine Coene
Keyword(s):  
Higher Education ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Academic Language ◽  
Acoustic Properties ◽  
Reference Level ◽  
Teaching Staff ◽  
Reference Levels ◽  
Classroom Acoustics ◽  
Content Type

PurposeAs oral communication in higher education is vital, good classroom acoustics is needed to pass the verbal message to university students. Non-auditory factors such as academic language, a non-native educational context and a diversity of acoustic settings in different types of classrooms affect speech understanding and performance of students. The purpose of this study is to find out whether the acoustic properties of the higher educational teaching contexts meet the recommended reference levels.Design/methodology/approachBackground noise levels and the Speech Transmission Index (STI) were assessed in 45 unoccupied university classrooms (15 lecture halls, 16 regular classrooms and 14 skills laboratories).FindingsThe findings of this study indicate that 41 classrooms surpassed the maximum reference level for background noise of 35 dB(A) and 17 exceeded the reference level of 40 dB(A). At five-meter distance facing the speaker, six classrooms indicated excellent speech intelligibility, while at more representative listening positions, none of the classrooms indicated excellent speech intelligibility. As the acoustic characteristics in a majority of the classrooms exceeded the available reference levels, speech intelligibility was likely to be insufficient.Originality/valueThis study seeks to assess the acoustics in academic classrooms against the available acoustic reference levels. Non-acoustic factors, such as academic language complexity and (non-)nativeness of the students and teaching staff, put higher cognitive demands upon listeners in higher education and need to be taken into account when using them in daily practice for regular students and students with language/hearing disabilities in particular.

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 .

Acoustical Comfort in Classrooms: Case Study at the University of Brasília

2018 ◽  
Author(s):  
Clarice C. Daga ◽  
Hetty N. C. C. Lobo ◽  
José A. P. C. Lobo ◽  
Carlos E. L. Melo
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Learning Activity ◽  
Sound Perception ◽  
Acoustic Comfort ◽  
Two Parameters ◽  
Teaching Learning ◽  
The University ◽  
Acoustic Conditions

The acoustic conditions in school spaces are fundamental for the success of the learning process. This article aims to present the results of acoustic comfort by the analytical method of 9 classrooms with different geometric characteristics of the University of Brasília. In classrooms the background noise limits are 40 to 50dBA and considering that the teacher’s voice reaches a certain 65 decibels we can highlight that it can be heard clearly by the students. However in an environment with a lot of reverberation of sounds the teacher will have to exert more effort to be understood. The sound perception in a room depends on the intensity and temporal relationship between the direct sound and the indirect sound reflected by the walls of the room, therefore, in the present study were verified two parameters namely the reverberation time and speech intelligibility. The results obtained were compared with the normative parameters of ANSI S12.60: 2010 and it was verified that all rooms are not suitable for teaching-learning activity. To guarantee an environment with better conditions of concentration and learning for the students, acoustic coverings were suggested in order to fit the normative limits.

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 Face mask type affects audiovisual speech intelligibility and subjective listening effort in young and older adults

2021 ◽  
Author(s):  
Violet Aurora Brown ◽  
Kristin J. Van Engen ◽  
Jonathan E. Peelle
Keyword(s):  
Older Adults ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Age Groups ◽  
Face Mask ◽  
Noise Levels ◽  
Listening Effort ◽  
Impaired Performance ◽  
Fine Grained ◽  
Mask Type

Identifying speech requires that listeners make rapid use of fine-grained acoustic cues—a process that is facilitated by being able to see the talker’s face. Face masks present a challenge to this process because they can both alter acoustic information and conceal the talker’s mouth. Here, we investigated the degree to which different types of face masks and noise levels affect speech intelligibility and the subjective effort involved for young (N=180) and older (N=180) adult listeners. We found that in quiet, mask type had little influence on speech intelligibility relative to speech produced without a mask for both young and older adult listeners. However, with the addition of moderate (-5 dB SNR) and high (-9 dB SNR) levels of background noise, intelligibility dropped substantially for all types of face masks in both age groups. Across noise levels, transparent face masks and cloth face masks with filters impaired performance the most, and surgical face masks had the smallest influence on intelligibility. Importantly, participants also rated the speech as more effortful in the masked conditions compared to unmasked speech, particularly in background noise. Although young and older adults were similarly affected by face masks and noise in terms of intelligibility and subjective listening effort, older adults showed poorer intelligibility overall and rated the speech as more effortful to process relative to young adults. This research will help individuals make more informed decisions about which types of masks to wear in various communicative settings.

Natural Speech Intelligibility in Theatres in Relation to Their Acoustics

2011 ◽  
Vol 18 (3-4) ◽  
pp. 293-311
Author(s):  
Maarten P.M. Luykx ◽  
Martijn L.S. Vercammen
Keyword(s):  
Background Noise ◽  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Speech Sound ◽  
Sound Level ◽  
Natural Speech ◽  
Noise Levels ◽  
Signal To Noise ◽  
Background Levels ◽  
Noise Ratio

There is a certain tendency in the design of theatres to make the halls quite large. From a perspective of natural speech intelligibility and strength of speech this is disadvantageous, because an actor's voice has a certain, limited loudness and consequently the signal-to-noise ratio at the listener may become too low. Based on the influence of signal/noise ratio on speech intelligibility, it is deduced that the strength G ≥ 6 dB and room volumes have to be limited to 4000–4500 m3 in order to maintain sufficient loudness for natural speech. Sound level measurements during performances with natural speech in a theatre have been performed, to determine background noise levels in the hall due to the audience and to investigate the signal-to-noise ratio of the actors voice at the audience. The background levels are mainly determined by installation noise and not by the influence of the audience.

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 Face mask type affects audiovisual speech intelligibility and subjective listening effort in young and older adults

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Violet A. Brown ◽  
Kristin J. Van Engen ◽  
Jonathan E. Peelle
Keyword(s):  
Older Adults ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Age Groups ◽  
Face Mask ◽  
Noise Levels ◽  
Listening Effort ◽  
Impaired Performance ◽  
Fine Grained ◽  
Mask Type

AbstractIdentifying speech requires that listeners make rapid use of fine-grained acoustic cues—a process that is facilitated by being able to see the talker’s face. Face masks present a challenge to this process because they can both alter acoustic information and conceal the talker’s mouth. Here, we investigated the degree to which different types of face masks and noise levels affect speech intelligibility and subjective listening effort for young (N = 180) and older (N = 180) adult listeners. We found that in quiet, mask type had little influence on speech intelligibility relative to speech produced without a mask for both young and older adults. However, with the addition of moderate (− 5 dB SNR) and high (− 9 dB SNR) levels of background noise, intelligibility dropped substantially for all types of face masks in both age groups. Across noise levels, transparent face masks and cloth face masks with filters impaired performance the most, and surgical face masks had the smallest influence on intelligibility. Participants also rated speech produced with a face mask as more effortful than unmasked speech, particularly in background noise. Although young and older adults were similarly affected by face masks and noise in terms of intelligibility and subjective listening effort, older adults showed poorer intelligibility overall and rated the speech as more effortful to process relative to young adults. This research will help individuals make more informed decisions about which types of masks to wear in various communicative settings.

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