Wed February 09, 2011 By: Drishya Rajan

hi, i am Drishya.i am a little bit confused with a question based on the reflection of is said that if an object is 17 m or more away from the source of sound we can hear the echo.but my question is 'when we put a drinking glass close to our mouth such that it covers our mouth and we make a sound it will be heard reflected even if it is not 17m awy from the source of does this happen?'

Expert Reply
Thu February 10, 2011
Dear student
When you place your mouth close to the glass and make a sound; the reflected sound you hear is not due to echo but due to 'reverberation'; sometimes in empty rooms also you can experience reverberation.
For echo to take place the minimum distance between the source of sound and listener should be 17m.
Hope this helps.
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