On December 14, 2016, the results of the study of the acoustic environment in one of the classrooms were presented at the Lyceum No. 1502 at the MPEI (Moscow): thanks to the creation of optimal acoustic conditions, it was possible to reduce the reverberation time in the room by half.
Acoustics specialists have measured the reverberation time [1] and compared the audibility and intelligibility of speech in a regular classroom and a classroom with a high level of acoustic comfort. Research results have confirmed that in a room with good acoustics, speech sounds clear and clear, which improves listening comprehension and thus increases learning efficiency. At the same time, the level of background noise is significantly reduced, which prevents students from concentrating, causes rapid fatigue and even provokes restless behavior, especially among younger students.
Director of the State Budgetary Educational Institution "Lyceum No. 1502 at MPEI", Honored Teacher of Russia, Laureate of the President of the Russian Federation, Doctor of Pedagogy, Professor Vladimir Lvovich Chudov noted: "Our Lyceum is a modern innovative institution in which students receive deep knowledge that opens wide horizons in their future adult life. The quality of education depends on many factors, among which comfortable learning conditions play an important role. A good acoustic environment is one of the components of comfort. It is well known that in many school premises the noise level is quite high. Acoustic classrooms have significantly lower noise levels, which is beneficial for teachers and student learning. We hope that our successful example will serve as an incentive to carry out acoustic modernization in other educational institutions."
Scientists from different countries of the world are studying the effect of acoustics on a person with great interest: numerous studies have shown that the lack of acoustics of premises negatively affects both the productivity of the learning process and the health of teachers. According to the American Acoustic Society, a 10 dB increase in background noise results in a 5-7% decrease in information comprehensibility on average. Teachers constantly experience increased stress, which negatively affects their hearing and speech organs, as well as their well-being in general. The US Association for Speech, Language and Hearing found that teachers are 32 times more likely to have problems with their vocal cords than people in other professions.
At the same time, German scientists have found that in a favorable sound environment, the perception of oral information by schoolchildren is significantly improved. Children are more willing to work in groups, which is explained by a 13 dB reduction in the noise level in classrooms with good acoustics (the noise energy has been reduced by 20 times). Where classes are focused on monologue (the teacher speaks, the students listen), this figure is 10 dB (research results from Heriot-Watt University, UK, and the University of Bremen, Germany). When measurements were taken in empty classrooms, the difference between the rooms (with and without acoustic decoration) in noise level was 3-5 dB. An additional increase of 7-8 dB was provided by the opposite Lombard effect (the library effect), that is, in a calm environment, people try to speak in low tones so as not to disturb the silence. The feeling of noise reduction by 10-13 dB can be compared to the onset of silence after a powerful fan is turned off in the room, or a truck has driven away from the window.
A supportive acoustic environment is especially important for sensitive children, that is, students with (often undetected) hearing impairments, non-native language students, and students with attention deficit hyperactivity disorder. According to the data provided in the report of the Scottish Government [2], the number of such pupils is up to 21% of the total number of children and adolescents attending educational institutions. Students with hearing problems, when moving from an ordinary classroom to a room with good acoustics, felt a significant improvement in hearing and, as a result, fully absorbed the teacher's explanation. Good acoustics has a positive effect on the physiological state of teachers. Heart rate (pulse 10 beats less than in regular classes) and the content of stress hormones in the blood are within the normal range [3].
Olga Titova, Business Development Manager of the ECOPHON division of Saint-Gobain, noted: “Saint-Gobain has a long history and has a wealth of knowledge in the field of creating a favorable acoustic environment: we take part in various studies, conduct training events for architects and share our experience with our Russian partners, as we consider this problem extremely urgent. After all, a room correctly equipped in terms of acoustics can increase the level of perception of oral speech by students by 25% and reduce the risk of developing occupational diseases among teachers by 75%."
[1] Reverberation time is the time it takes for a sound to decay by 60 dB. In a favorable acoustic environment, only direct sound is heard (from the speaker to the listeners). In this case, the so-called late reflections do not occur, that is, sound waves chaotically reflected from the walls, ceiling and floor, which reduce the audibility and intelligibility of speech, and also create background noise.
[2] Report by the Scottish Government on the enactment of the Education Act 2004 and the Supplementary Education Support Act.
[3] Research from the University of Bremen.
