Investigation of the Appropriate Reverberation Time for Lower-Grade Elementary School Classrooms Using Speech Intelligibility Tests

Abstract

Because speech recognition performance is significantly lower at the age of nine or younger, the acoustic performance standards of classrooms for young children should be investigated. This study derives the appropriate reverberation time for lower-grade elementary school classrooms in Korea. A virtual sound field was created by computer modeling using normalized classrooms of Korean elementary schools. A total of five classrooms with reverberation times from 0.6 s to 1.2 s were produced by varying the sound absorption coefficient of the ceiling. Auralized sounds were produced by synthesizing anechoic sounds of words in a virtual sound field. Speech intelligibility tests were undertaken with 20 young students, aged nine. As a result, it was concluded that the reverberation time suitable for lower-grade classrooms of elementary schools should be below 0.6 s because test scores were significantly lower when RT was longer than this value.

Determination of the Sound Absorption Area Inside an Elementary Classroom Using Three Acoustical Methods: Computer Modeling, 1/10-Scale Model Experiment, and Field Acoustic Measurement

“…Elementary classrooms in Korea should have an RT of <0.6 s [2]. Table 6 shows the configurations that produced RTs of ≤0.6 s. The 1/10-scale model yielded a shorter RT than the other experimental methods.…”

“…The hearing abilities of lower elementary students must be considered when designing classrooms to facilitate their education. The following acoustic standards for lower elementary students have been proposed in Korea to ensure speech intelligibility [2,3]: a reverberation time (RT) of <0.6 s (unoccupied) and background noise level of <35 A-weighted decibels (dB(A)) for a classroom volume of <185 m 3 . Ensuring that the acoustic environment of lower elementary classrooms meets these standards will help to improve the learning efficiency of students.…”

“…In Equation (1), p(t) means the instantaneous sound pressure of the impulse response measured at the measurement point. The equation for C 50 , which is frequently used in classrooms to assess speech clarity, is shown in Equation (2). C 50 can also be calculated using D 50 , as shown in ISO3382-1.…”

Classroom architectural design evolution: Acoustic evaluation of public-school classrooms in Malaysia

“…Listening in an environment with poor acoustics necessitates greater concentration [11] which could lead to a decrease in students learning achievement [8]. Thus, students learning development is greatly influenced by the classroom acoustic quality [12]. On the other hand, the acoustics of the classroom have a substantial impact on the teacher's well-being.…”

Investigation of the Acoustics Performance of the University’s Lecture Rooms by using Economical and Feasible Design Improvement Strategies

“…All the surfaces mentioned above have low absorption coefficients, thus more sound energy is reflected within the lecture rooms. A study by Jo et al (2022) found that classrooms wall equipped with soundabsorbing boards demonstrate optimal reverberation time (RT) conditions in comparison to classrooms with painted cement surface. Furthermore, classes that utilize carpet flooring attained the recommended RT value of 0.6 seconds, in contrast to classrooms equipped with marble flooring (Ahmad, 2020).…”