Assessing Acoustic Conditions in Hybrid Classrooms for Chinese Speech Intelligibility at the Remote End

Blended Synchronous Learning helps teachers and students communicate without geographical restrictions. The effect of communication between the face-to-face end and the remote end was not only affected by the performance of the equipment but also by the acoustic conditions in the classroom. This pap...

Full description

Saved in:
Bibliographic Details
Main Authors: Qian Li, Nan Li, Yan Wang, Zheng Li, Mengyun Tian, Yihan Zhang
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Buildings
Subjects:
Online Access:https://www.mdpi.com/2075-5309/15/11/1909
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Blended Synchronous Learning helps teachers and students communicate without geographical restrictions. The effect of communication between the face-to-face end and the remote end was not only affected by the performance of the equipment but also by the acoustic conditions in the classroom. This paper measured the acoustic parameters in the hybrid classrooms and conducted subjective speech intelligibility tests. It was found that for the hybrid classroom with a decentralized sound reinforcement system, the background noise level was high because lots of equipment was needed for synchronous learning. The speech intelligibility scores of the remote end were lower than those at the face-to-face end. Acoustic parameters of reverberation time (RT) and excessive signal-to-noise ratio (SNR) showed a negative correlation with speech intelligibility scores in the remote end. It was recommended that the sound pressure level (SPL) of the sound reinforcement system should not be too high and that appropriate sound absorption treatment be performed. The size of the hybrid classroom should be controlled to prevent the sound that arrived 50 ms after the direct sound from arriving. When SNR was 33 dB(A) for hybrid classrooms, which had a good performance in the face-to-face end with the speech intelligibility scores, T<sub>20</sub> should be within 0.8 s to achieve the target value of 83% for SI scores at the remote end.
ISSN:2075-5309