It seems that in my classroom I have to almost shout to be heard. The noise that competes with speech comes generally from two sources, the people in the room and their activity and the ventilation noise. The reverberation in the room depends on the surfaces in the classroom that can reflect sound. Generally, when we design classrooms or correct their acoustics, we first start with the ventilation noise and do everything possible to reduce it. Frequently, that requires that we change the type of ventilation unit in the room.
Some ventilators are much noisier than others.
To reduce the level of noise from people and other sources in the room, we need to treat the surfaces so that they absorb more sound. This sound absorption reduces the amount of vibration. Frequently, this is accomplished with a sound absorbent ceiling and sound absorbent panels or other finishes on the walls. However, it is important to recognize that placing too much sound absorption in a room or placing it in incorrect locations can work to the detriment of the ability to hear speech at great distances from the person talking. A. First of all, we know the levels at which people normally speak.