摘要 |
A telephone apparatus for use in a conference room has a housing, with a vertical central axis, with a loudspeaker at the upper end, coaxial with the vertical axis, and a microphone at the lower end. The loudspeaker faces upward with an unrestricted outlet and is omnidirectional in output. The microphone faces downward and is coaxial with the vertical axis, being sensitive only to airborne vibration only. The microphone is surrounded by an inclined surface extending outwardly and upwardly at an angle of about 30 DEG , and has an omnidirectional sensitivity. The housing is supported with the microphone inlet about 1/2 inch above a surface, which can be the surface of a base member attached to the housing. The minimal peripheral distance from the center line of the speaker to the center line of the microphone, around the housing, is about 15 inches, for good acoustic separation. A resonator can be attached to the microphone inlet.
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