Moscow Lyceum No. 1502

Project: Moscow Lyceum No. 1502 at Moscow Power Engineering Institute

Country/city: Russia / Moscow

Production year: 2016

Project size: 50 

Acoustic evaluation in Moscow Lyceum No. 1502: Silence in class gets the highest grade

On 14 December 2016 the results of an evaluation of the acoustic environment in one of the classrooms at the state educational institution, Lyceum No. 1502 at Moscow Power Engineering Institute, were presented. By optimising the acoustic conditions it was possible to reduce the reverberation time by a factor of two. 

Specialists in acoustics measured the reverberation time* and compared the audibility and intelligibility of speech in an ordinary classroom and a classroom with a high level of acoustic comfort. The results confirmed that in a room with good acoustics, speech is heard distinctly and clearly, which improves the perception of spoken information and thus increases the effectiveness of learning. It also significantly decreased the level of background noise that disturbs the concentration of pupils, causes rapid fatigue and even restlessness, especially among younger pupils. 

The principal of Lyceum No. 1502, doctor of educational science and recipient of an award from the President of the Russian Federation, Professor Vladimir L. Chudov, says: “Our lyceum is a modern innovative institution, where the pupils receive in-depth knowledge, preparing them for their future adult lives. The quality of education depends on many factors, one being comfortable learning conditions. A good acoustic environment is an important part of that. It is well known that the noise level is quite high in many classrooms. In classes with acoustic absorbers the noise level is significantly lower, which has a positive influence on the teachers’ work and the pupils’ learning. Let us hope that our successful example will stimulate other educational institutions to upgrade the acoustic environment.” 

The impact of acoustics on human beings is a matter studied with great interest by scientists all over the world: numerous studies have shown that unsatisfactory acoustics in a room have a negative effect both on the learning process and on the teachers’ well-being. According to the Acoustical Society of America, an increase in the background noise by 10 dB will lead to an average reduction in the comprehension of information by 5–7 per cent. Teachers are constantly experiencing increased stress, which has a negative influence on their hearing and speech abilities, as well as their general well-being. The American Speech-Language-Hearing Association has found that teachers are 32 times more likely to have problems with their vocal chords than people of other professions. 


German scientists have also come to the conclusion that
in a favourable acoustic environment, pupils’ perception of oral information is significantly improved. Children are more willing to work with group assignments, which is explained by a reduction in noise level by 13 dB in classes with good acoustics (the sound energy was reduced by a factor of 20). When the lessons are dominated by monologues (the teacher speaks and the pupils listen), the figure is 10 dB (results from Heriot-Watt University, UK, and the University of Bremen, Germany). When the measurements were carried out in an empty classroom, the difference between the noise levels in the rooms (with and without acoustic absorbers) was 3–5 dB. An additional increase of 7–8 dB is provided by the Lombard reflex (the library effect), which implies that in a quiet surrounding people tend to speak in a hushed voice so as not to break the silence. The impression of a noise reduction of 10–13 dB may be compared with the onset of silence when a powerful fan is turned off in a room, or after a truck has passed the window. 

A favourable acoustic environment is of special importance for “sensitive” children, i.e. pupils with hearing impairments (often undetected), pupils who study in a language other than their native language, as well as pupils with attention deficit hyperactivity disorder (ADHD). According to data cited in a report by the Scottish Government**, such pupils make up 21 per cent of the total number of children and adolescents attending educational institutions. Moving from a conventional classroom to one with good acoustics, pupils with hearing problems noted a significant improvement in audibility, and were consequently fully able to take in the teacher’s explanations. Good acoustics have a positive impact on the teachers’ state of health. The heart rate (pulse 10 beats lower than in conventional classrooms) and levels of stress hormones in the blood are within the normal range***. 

Saint-Gobain has a century-long history and is in possession of extensive, in-depth knowledge in the field of creating a favourable acoustic environment. We take part in various studies, arrange educational events for architects and share our collected experience with our Russian partners, as we consider this to be an extremely important issue. After all, the correct acoustical equipment in any premises makes it possible to raise the perception level of spoken language amongst pupils by 25 per cent and lower the risk of occupational diseases developing among teachers by 75 per cent”, says Olga Titova, business development manager of the Saint-Gobain subsidiary Ecophon.



*Reverberation time is the time it takes for a sound to drop by 60 dB. In a satisfactory acoustical environment, the direct sound (from the speaker to the audience) is the only sound to be heard. Moreover, there are no so-called late reflections – randomly reflected sound waves from the walls, ceiling and floor – that reduce audibility and intelligibility, as well creating background noise.

** Report of the Scottish Government while taking into force the Education (Additional Support for Learning) Act 2004.

***Research by the University of Bremen.