Consider the following statements regarding 'Reverberation': 1. It is the persistence of sound in a big hall due to repeated reflection. 2. Excessive reverberation is highly desirable in concert halls to enhance sound quality. 3. Sound-reflecting materials like glass are used to reduce reverberation. Which of the statements given above is/are correct?

The correct option is (a). Explanation Reverberation is an acoustic phenomenon characterized by the persistence of sound in an enclosed space as a result of multiple reflections from surfaces such as walls, ceilings, and floors. Statement-wise Analysis: - Statement 1 is Correct: In a large hall, sound waves undergo repeated reflection from the walls and ceiling. This results in the sound persisting for a duration even after the source has ceased. This persistence of sound due to multiple reflections is technically termed reverberation. - Statement 2 is Incorrect: While a specific, limited amount of reverberation is necessary to prevent a hall from sounding "dead," excessive reverberation is highly undesirable. It causes the overlapping of sounds, making speech unintelligible and music distorted or blurred. - Statement 3 is Incorrect: To reduce reverberation, the surfaces of the enclosure must absorb sound energy rather than reflect it. Therefore, sound-absorbing materials like compressed fibreboard, rough plaster, heavy curtains, and carpets are utilized. Materials like glass are hard and smooth, acting as efficient reflectors, which would sustain or increase reverberation. Key Takeaway: Reverberation is the persistence of sound caused by repeated reflections. Acoustic design aims to control this by using sound-absorbing materials to prevent sound blurring, ensuring clarity in auditoriums and concert halls.

NCERT Class 9 Science — Chapter 5: Sound

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Consider the following statements regarding 'Reverberation':

It is the persistence of sound in a big hall due to repeated reflection.
Excessive reverberation is highly desirable in concert halls to enhance sound quality.
Sound-reflecting materials like glass are used to reduce reverberation.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is (a).

Explanation

Reverberation is an acoustic phenomenon characterized by the persistence of sound in an enclosed space as a result of multiple reflections from surfaces such as walls, ceilings, and floors.

Statement-wise Analysis:

Statement 1 is Correct: In a large hall, sound waves undergo repeated reflection from the walls and ceiling. This results in the sound persisting for a duration even after the source has ceased. This persistence of sound due to multiple reflections is technically termed reverberation.
Statement 2 is Incorrect: While a specific, limited amount of reverberation is necessary to prevent a hall from sounding "dead," excessive reverberation is highly undesirable. It causes the overlapping of sounds, making speech unintelligible and music distorted or blurred.
Statement 3 is Incorrect: To reduce reverberation, the surfaces of the enclosure must absorb sound energy rather than reflect it. Therefore, sound-absorbing materials like compressed fibreboard, rough plaster, heavy curtains, and carpets are utilized. Materials like glass are hard and smooth, acting as efficient reflectors, which would sustain or increase reverberation.

Key Takeaway:
Reverberation is the persistence of sound caused by repeated reflections. Acoustic design aims to control this by using sound-absorbing materials to prevent sound blurring, ensuring clarity in auditoriums and concert halls.

Your note

More from Chapter 5: Sound

Consider the following statements regarding the propagation of sound: 1. The disturbance created by a source travels through the medium to the listener. 2. Sound waves are characterized as non-mechanical waves. 3. A material medium is mandatory for the transmission of sound. Which of the statements given above are correct?

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With reference to the characteristics of a sound wave, consider the following statements: 1. The distance between two consecutive compressions is called the wavelength. 2. The time taken for one complete oscillation is called the frequency. 3. The SI unit of frequency is Hertz. Which of the statements given above are correct?

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Consider the following statements regarding Ultrasound: 1. It refers to sounds with frequencies higher than 20 kHz. 2. Ultrasound waves scatter immediately when they encounter obstacles. 3. Ultrasound is incapable of penetrating metal blocks to detect flaws. Which of the statements given above is/are correct?

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The cleaning action of an ultrasonic cleaner is primarily achieved through:

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With reference to medical applications of sound, consider the following statements: 1. Echocardiography uses ultrasonic waves to form an image of the heart. 2. Ultrasonography uses X-rays to detect stones in the gall bladder. 3. Ultrasound can be used to break kidney stones into fine grains. Which of the statements given above are correct?

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Keep practising Chapter 5: Sound

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The correct option is (a).

Explanation

Reverberation is an acoustic phenomenon characterized by the persistence of sound in an enclosed space as a result of multiple reflections from surfaces such as walls, ceilings, and floors.

Statement-wise Analysis:

Statement 1 is Correct: In a large hall, sound waves undergo repeated reflection from the walls and ceiling. This results in the sound persisting for a duration even after the source has ceased. This persistence of sound due to multiple reflections is technically termed reverberation.
Statement 2 is Incorrect: While a specific, limited amount of reverberation is necessary to prevent a hall from sounding "dead," excessive reverberation is highly undesirable. It causes the overlapping of sounds, making speech unintelligible and music distorted or blurred.
Statement 3 is Incorrect: To reduce reverberation, the surfaces of the enclosure must absorb sound energy rather than reflect it. Therefore, sound-absorbing materials like compressed fibreboard, rough plaster, heavy curtains, and carpets are utilized. Materials like glass are hard and smooth, acting as efficient reflectors, which would sustain or increase reverberation.