Do room volume affects sound?



The bigger the room, the longer the reflection distance / time / decay.

Sound passing through air will experience high frequency air absorption more severe than low frequency.

Try to remember the Sound Reflections Demo Video!!!

It is to be noted that sound looses energy more by reflecting / turning / bending than compared to travelling long distances.

For example, large halls have echo. In order for a sound to be classified as echo, it must be identical to the 1st arrival sound and late by more than 80ms with sufficiently large signal strength.

One should question and wonder, why in a large hall, where the sound travelling from the front stage to the rear of the hall and coming back a total of 60 meters is still so loud.

Assuming sound source from stage is 100dB SPL. After travelling 60 meters it would have lost 20Log(60) = 35.56 dB SPL

100 - 35.56 = left with 64.44 dB SPL

Sound travelling 60 meters = 60/347.3 = 0.172 seconds = 172 milliseconds

During this time 172 milliseconds, it only suffer lost of energy through reflection once. Where by most high frequency lost is through air humidity absorption.

In reality the strength of returning echo is a PRODUCT of room acoustics properties (please remember the video), where by some parts of the room acts like a mirror and concentrate the reflections energy.

In a small environment is completely different. Take a car for example, there are never any echo occurring. This is because once a sound is released it would reach the next reflecting surfaces very early and looses it's energy through bending etc. 

Again assuming the reflection in a car can travel 60 meters and that from window to window is 1.5 meters. 60/1.5 = 40. During this time, it would have reflected 40 times more compared to the hall above. Therefore a small environment like car, house, regular rooms etc do not have echo as well as long reverberation time.



  1. Introduction to Acoustics
  2. What are acoustics?
  3. How is sound created?
  4. What are the definitions of sound?
  5. How do sound travel?
  6. What is wavelength?
  7. Is sound a science?
  8. How do sound disperse?
  9. How long for sound to reach us?
  10. Do sound reflect?
  11. How do sound reflect?
  12. Do room volume affects sound?
  13. Do room shape affects sound?
  14. What is sound absorption?
  15. What is sound proof?
  16. How do sound wave summate or negate?
  17. Why do we need to know all these?



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