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.

The Effect of Source Location, Posture and Language on Speech Intelligibility in Goan Churches

2009 ◽  
Vol 16 (3) ◽  
pp. 283-297 ◽  
Author(s):  
Menino A. S. M. P. Tavares ◽  
S. Rajagopalan ◽  
Satish J. Sharma ◽  
António P. O. Carvalho
Keyword(s):  
Speech Intelligibility ◽  
English Language ◽  
Field Measurements ◽  
Source Location ◽  
Transmission Index ◽  
Speech Transmission ◽  
Catholic Churches ◽  
Predictive Relationship ◽  
The Church ◽  
Made In

The results presented here are based on field measurements carried out in six Catholic churches (Goa, India). Rapid Speech Transmission Index ( RASTI) and Subjective Speech Intelligibility ( SSI) measurements were made in four different seating zones of a church for three speech source locations (altar, pulpit, high altar), two languages (English, Konkani) and two postures (standing, sitting). The effects of language and postures were not significant. The altar location and the sanctuary of the church were preferable for speech intelligibility. Although the altar location showed better averages than the other speech source locations, the best predictive relationship between RASTI and SSI was the exponential growth of RASTI for the high altar source location with SSI for the English language.

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 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.

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.

Binaural speech-to-noise loudness ratio at the speech reception threshold in vehicles

2021 ◽  
Vol 69 (2) ◽  
pp. 173-179
Author(s):  
Nilolina Samardzic ◽  
Brian C.J. Moore
Keyword(s):  
Speech Intelligibility ◽  
New Method ◽  
Traditional Methods ◽  
Speech Reception ◽  
Typical Error ◽  
Transmission Index ◽  
Speech Transmission ◽  
Articulation Index ◽  
Speech Intelligibility Index ◽  
Binaural Listening

Traditional methods for predicting the intelligibility of speech in the presence of noise inside a vehicle, such as the Articulation Index (AI), the Speech Intelligibility Index (SII), and the Speech Transmission Index (STI), are not accurate, probably because they do not take binaural listening into account; the signals reaching the two ears can differ markedly depending on the positions of the talker and listener. We propose a new method for predicting the intelligibility of speech in a vehicle, based on the ratio of the binaural loudness of the speech to the binaural loudness of the noise, each calculated using the method specified in ISO 532-2 (2017). The method was found to give accurate predictions of the speech reception threshold (SRT) measured under a variety of conditions and for different positions of the talker and listener in a car. The typical error in the predicted SRT was 1.3 dB, which is markedly smaller than estimated using the SII and STI (2.0 dB and 2.1 dB, respectively).

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

scholarly journals Archaeoacoustic Examination of Lazarica Church

Acoustics ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 423-438 ◽  
Author(s):  
Zorana Đorđević ◽  
Dragan Novković ◽  
Uroš Andrić
Keyword(s):  
Speech Intelligibility ◽  
Acoustic Analysis ◽  
Sound Field ◽  
Simulation Software ◽  
Central Dome ◽  
Acoustic Effect ◽  
Additional Information ◽  
Medieval Church ◽  
Transmission Index ◽  
Speech Transmission

The acoustic analysis provides additional information on building tradition and related indoor practice that includes sound, thus deepening our understanding of architectural heritage. In this paper, the sound field of the Orthodox medieval church Lazarica (Kruševac city, Serbia) is examined. Lazarica is a representative of Morava architectural style, developed in the final period of the Serbian medieval state, when also the chanting art thrived, proving the importance of the aural environment in Serbian churches. The church plan is a combination of a traditional inscribed cross and a triconch. After the in situ measurement of acoustic impulse response using EASERA software, we built a computer model in the acoustic simulation software EASE and calibrated it accordingly. Following the parameters (reverberation time (T30), early decay time (EDT) and speech transmission index (STI)), we examined the acoustic effect of the space occupancy, central dome and the iconostasis. In all the cases, no significant deviation between T30 and EDT parameter was observed, which indicates uniform sound energy decay. Closing the dome with a flat ceiling did not show any significant impact on T30, but it lowered speech intelligibility. The height of iconostasis showed no significant influence on the acoustics of Lazarica church.

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