| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an inexpensive earphone microphone which can be reduced in size and has an echo suppression function.SOLUTION: An earphone microphone includes one speaker, a differential microphone, and a body housing. The differential microphone has first and second sound collection holes. The body housing includes: first and second openings communicating with an outside; a first acoustic space communicating with the first opening; and a second acoustic space communicating with the second opening. Sound to be input to the first sound collection hole is propagated in the first acoustic space. The speaker is arranged in the second acoustic space, and sound to be input to the second sound collection hole is propagated in the second acoustic space. The second acoustic space functions as a Helmholtz resonator with respect to sound to be propagated by way of the second opening.</p> |
