20150055790 | ACOUSTIC SYSTEM - An acoustic system includes: a first customer-side microphone; a first counselor-side microphone; a first sound changing unit; a first loudspeaker; a second customer-side microphone; a second counselor-side microphone; and a second loudspeaker. Between the second loudspeaker and the first customer-side microphone, a first sound transmission path is provided. Also, between the second loudspeaker and the first counselor-side microphone, a second sound transmission path is provided. These sound transmission paths have substantially the same length. The first sound signal generated by the first customer-side microphone is made to have a phase substantially opposite to that of the second sound signal generated by the first counselor-side microphone, and the sound signals are added together. | 02-26-2015 |