Have you ever wondered about a sudden silence in a crowd? Is this the so-called hush or silence after 20 minutes of an hour? There are many explanations about silence after noise, ranging from superstition, psychological, and physiological to empirical evidence. Superstitious belief says that there will be a sudden silence in a noisy crowd because of the angel’s singing and people tend to listen. Some associate it with the final labored breath on the death of Lincoln. While, in the perspective of psychology and physiology, this is associated with crowd sensing, cognitive fatigue or crowd synchronization. Based on ancestral records they associate the sudden silence as a protection postulate where they sense the danger and gather their senses to observe the environment.
Scientifically speaking silence could happen in between noise, sound waves are mechanical waves that require material to travel. We create noise through vocal vibrations, rhythmic patterns of movement, or by just simply making footsteps. Imagine a wave, like curly hair, it has a high point which is called the crest, and a low point which is the trough. If there are two passing waves at the same time in opposite directions it could create interference that now turns out to be a cancellation of sound where silence occurred. Like two persons bumping into each other which cancels their motion and makes a pause.
Applying the principles of interference in the study of acoustics is similar to the mechanics and functionalities of earphones. Upon wearing your earphones, there is a little diffraction where minimal blocking of sounds happens, minimizing the sound that you hear externally. Upon playing the sounds now, there are two sounds produced. First, the external sounds created by people outside, and second the sound you play using your device. These sounds coming in opposite directions creates interference and cancels the sound in between. This causes the sounds you played on your device to be heard only, while wearing the earphones.
Technical advances including earphones are taking a pause for silence on external crowds and noise, which is essential not only for people’s comfort but also for inner peace.
by: Angel Garganta