Acoustical Issues in Classrooms

Most typical size classrooms may not seem loud, however, when you add a couple dozen students (regardless of age) with chairs, tables and desks, etc, things get loud.

Many classrooms tend to have tile floors with a drop tile, T bar ceiling. While the ceiling tile is helpful to absorb these tiles are usually of a low grade that does not have a very high absorption co-efficient.

Shelves and cupboards can help break some sound but also can create cavities above or beside that actually amplifies some frequencies.

Typically most of these classrooms get loud throughout the day. This is fatiguing for the teacher, educational assistant(s) and students. Students get agitated and tend to act out in a louder ambient environment.

Music or Drama Classrooms require a higher standard of isolation from other classrooms and greater clarity within. Music classrooms have a higher sound pressure level within the room, particularly with instrumental programs.

Acoustical Fundamentals

The acoustical nature of rooms with these characteristics, exhibit high ambient (sound) levels across the frequency spectrum. Fundamental low frequencies are powerful and excite adjacent, upper harmonic frequencies.

Certain frequencies are aggravating to human hearing. This is often a complex harmonic group of frequencies formed on top a fundamental frequency that is most distracting. By reducing or eliminating foundational frequency problems, ambient sounds become much less annoying and fatiguing.

Impact

As the overall volume or ambient sound level of a room is decreased, it is easier to hear throughout the space. In electronics, we often refer to a specification called “ signal to noise.” This is the amount of signal in relation to the noise produced by the circuit or product. This is the same concept for the acoustical environment of a room; if the noise in a space is reduced, you hear more “signal.” As a result of eliminating problem reflections and echoes, every little sound is not amplified to add to the acoustical noise of the room.

A classroom that does not have noticeable echoes and a balanced frequency response will be a quieter room to speak in. Speaking across the room no longer requires your voice to be raised.

Formerly unclear student responses become more audible.

A calmer less frustrating environment maintains better behavior.

Communication is improved resulting a more effective teaching time with less frustration and energy spent.