Few things irritate us more than exposure to excessive noise or inability to hear what we need to hear. Whether it's a nearby construction site, highway traffic, air conditioning, or a neighbor learning saxophone, research shows that noise can contribute to cardiovascular disease, high blood pressure, headaches, hormonal changes, sleep disturbance, reduced physical and mental performance, and the reduction of well-being. On the other hand, in an acoustically "comfortable" environment, in addition to listening to what we want, we focus better and feel calmer.
The concern about creating acoustically comfortable environments is often relegated to cinemas, concert halls and recording studios. But it is particularly important in learning environments, such as classrooms, as it directly influences the teaching-learning relationship. Acoustic discomfort can harm the process of knowledge acquisition, interfering with attention and worsening student-teacher communication.
Studies shows that uncomfortable classrooms cause discomfort and mood swings, contributing to increased stress and tiredness in students as well as decreased cognitive skills. Due to acoustic interference from outside environments in the classroom, the need to speak louder causes vocal and auditory exhaustion for teachers and students.
To better understand the issues surrounding acoustics, it is important to know some essential concepts. Sound waves, when intercepted by a receiver such as the human ear, are collected and transmitted as information to the brain: that is, they are 'heard'. While acoustic intensity is given in decibels (dB), the tone of the sound is expressed as "frequency" through the Hertz unit (Hz). The healthy human ear is sensitive to a very wide range of frequencies, from about 20Hz to 20,000Hz. Below and above this range are infrasound and ultrasound, respectively.