{"id":136494,"date":"2022-04-08T13:34:16","date_gmt":"2022-04-08T08:04:16","guid":{"rendered":"https:\/\/www.aakash.ac.in\/blog\/?p=136494"},"modified":"2023-03-25T17:12:40","modified_gmt":"2023-03-25T11:42:40","slug":"what-is-reverberation-definition-from-ncert-class-9-science","status":"publish","type":"post","link":"https:\/\/www.aakash.ac.in\/blog\/what-is-reverberation-definition-from-ncert-class-9-science\/","title":{"rendered":"What is Reverberation? Definition from NCERT Class 9 Science"},"content":{"rendered":"

Sound is an interesting phenomenon. It has various aspects, and all of them make one ponder upon them for some time. For instance, there is a difference in the sound of a movie when you watch it in a theatre and when you watch it at home on your desktop or TV.<\/span><\/p>\n

The difference in the sound is not just because of the volume levels but also because of the time for which the sound prevails.<\/span><\/p>\n

You can notice the same persistence of sound when attending an assembly in a closed auditorium or enjoying a musical concert in an enclosed hall. All these examples are applications of one of the interesting facts about sound ‘Reverberation’<\/a>. This article describes the definition of reverberation from NCERT class 9 Science<\/a>.\u00a0<\/span><\/p>\n

What is the sound?<\/h3>\n

A form of mechanical energy that propagates as a wave in the form of compressions and rarefactions in the medium is known as sound. These waves are produced through the vibration of objects and create the sensation of hearing.<\/span><\/p>\n

You can check out the NCERT Solutions for Class 9 Science Chapter 12 Sound.\u00a0<\/a><\/p>\n

What is an echo?<\/h3>\n

The echo is simply a reflection of the sound wave. When a sound wave collides with a hard surface such as a wall, mountain, or fence, the wave gets reflected. The reflected wave arrives at a listener with a delay. The delay in the wave is directly proportional to the distance of the reflecting surface from the source of the sound and the listener.<\/span><\/p>\n

When there are multiple surfaces from which the sound wave can get reflected at suitable distances, it gets reflected multiple times, resulting in multiple reflections.\u00a0<\/span><\/p>\n

Reverberation<\/h3>\n

When there are multiple surfaces with suitable distances for sound to collide with, multiple reflections of sound occur. Since the wavelength of sound is much longer than that of light, repeated reflection results in the persistence of sound even after the source have stopped, called reverberation. The NCERT class 9 Science definition of reverberation states the following: The persistence of sound caused by the multiple sound reflections even after the source has stopped is called reverberation.\u00a0<\/span><\/p>\n

When the time period between original and reflected sound is less than 0.1 sec, reverberation occurs. Since the reflected sound stays longer than the original sound, the original sound cannot be distinguished from the reflected sound. When the sound gets reflected by several sources, the reflections pile up and start reducing gradually as the sound gets absorbed by the surfaces.<\/span><\/p>\n

To clearly understand the chapter ‘Sound’ of the NCERT class 9, students should make sure they study the <\/span>important concepts<\/span><\/a>.<\/span><\/p>\n

Difference between echo and reverberation<\/h3>\n

Echo and reverberation are often confused with being one. However, there is some difference between the two.<\/span><\/p>\n

Reverberation occurs due to the multiple reflections of a sound wave resulting in the persistence of the sound even after the source sound has stopped. A human brain cannot distinguish between the original and reflected sounds due to the short time difference between the two sounds received by the ear. The brain thus perceives it as one continuous sound.<\/span><\/p>\n

Whereas echo is just a pulse of sound heard twice. A delay of about 50ms or more between the original and reflected sounds falling on the ear helps the human brain distinguish between the two waves.<\/span><\/p>\n

Advantages of Reverberation<\/h3>\n

Reverberation is a phenomenon related to the multiple reflections of the sound wave. When in an auditorium, the overlapping of sound waves makes a difference in the effect of sound.\u00a0<\/span><\/p>\n

In an orchestra hall or theatre, reverberations enhance the quality of sound manifold. It makes the music pleasant and with the right amount of reverberation employed. Sound engineers are employed while constructing these halls to ensure the optimum effect of reverberation.<\/span><\/p>\n

Disadvantages of Reverberation<\/h3>\n

Suppose reverberation of sound takes place in a normal room without any proper design or sound-absorbing surfaces. In that case, the sound reflections become repetitive, and the sound does not disappear for a long period.\u00a0<\/span><\/p>\n

In this case, the listener happens to listen to both the original sound and the reflected sound. And if there is enormous reverberation, the sound results in chaos giving rise to unpleasant sounds.<\/span><\/p>\n

Applications of Reverberation<\/h3>\n

Reverberation is employed in various music-related areas. The music or speech in a space with a sound reflective surface creates reverberation naturally.<\/span><\/p>\n

It is used artificially to stimulate reverb through certain means, including a chamber reverberator, a plate reverberator, a spring reverberator, and a digital reverberator. Plate reverberators are designed using metal plates to vibrate and can be used as an alternative to speakers. The concept of a reverberator is useful in a wide range of aspects.<\/span><\/p>\n

Following are certain applications of multiple reflections of sound:<\/span><\/p>\n