Reverberation

Reverberation, often called reverb, is a special sound effect. It happens when a sound keeps going after it stops. This is because the sound bounces off walls, furniture, and people. These reflections build up and slowly fade away until the sound disappears.

This effect is important in designing places like concert halls and classrooms. The time it takes for the sound to fade, called the reverberation time, needs to be just right. For example, a music hall needs longer reverb to make music sound full, while a classroom needs shorter reverb so people can hear and understand speech clearly.

Reverberation happens both naturally and with special effects. When you sing, talk, or play an instrument in a room with hard surfaces, the sound naturally reverberates. People can also create reverb using special effects that copy how sound travels and reflects in real spaces.

While reverb can make recorded sounds sound more natural, it can also make it hard to understand speech, especially with background noise. This can be challenging for people who have trouble hearing or use hearing aids. Scientists and engineers work on ways to reduce unwanted reverberation to make communication clearer.

Reverberation time

Reverberation time is how long it takes for sound to fade away in a room after the sound stops.

It is measured as the time it takes for the sound to get quieter by 60 decibels (dB). This is called T₆₀. In the past, scientists used special tools to measure this time. They found that bigger rooms take longer for sound to fade, and rooms with more objects that absorb sound have shorter reverberation times.

The right reverberation time depends on what kind of music or speech is played. For speaking, shorter times help people understand words better. For music, it can make the sound richer. Objects in the room, like furniture and people, also affect how long sound lasts.

In music

Reverberation is a common sound effect in music, used since the 10th century in plainsong. Gregorian chant may have begun because of the long echoes in big cathedrals.

Today, we can add artificial reverberation to music using reverb effects. These effects copy natural echoes using echo chambers, vibrations through metal, and digital tools.