Patent ID: 8462974

Claim:
An apparatus for transmitting and receiving sound comprising: a sound waveguide which is a pipe formed with one opening and an other opening, wherein at least two or more through holes are formed on the pipe by passing therethrough, a first sound is inputted into said one opening and a second sound is inputted into said other opening; a sound output unit disposed at said one opening of the sound waveguide to output the first sound to the sound waveguide; and a directional microphone for detecting the second sound by the through holes of the sound waveguide, wherein the first sound is a sound advancing from the sound output unit to an ear drum, the second sound is a sound generated from vibration of the ear drum by utterance of a user, and the first sound and the second sound cross in the directional microphone, and wherein there are two through holes at the sound waveguide, and the directional microphone has two ports, each port having a different detection sensitivity of sound and communicates with the two through holes, and the sound output unit is adjacent a port having a lower detection sensitivity.