For large concerts, loudspeakers are sometimes used
Chapter 16, Problem 16.86(choose chapter or problem)
For large concerts, loudspeakers are sometimes used toamplify a singers sound. The human brain interprets soundsthat arrive within 50 ms of the original sound as if they camefrom the same source. Thus if the sound from a loudspeakerreaches a listener first, it would sound as if the loudspeakeris the source of the sound. Conversely, if the singer is heardfirst and the loudspeaker adds to the sound within 50 ms,the sound would seem to come from the singer, who wouldnow seem to be singing louder. The second situation isdesired. Because the signal to the loudspeaker travels at thespeed of light (3 X 108m/s), which is much faster thanthe speed of sound, a delay is added to the signal sent tothe loudspeaker. How much delay must be added if theloudspeaker is 3.0 m behind the singer and we want its soundto arrive 30 ms after the singers?
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