| 摘要 |
<p>A telephone adapter provides high acoustic amplification for sound to be transmitted over a telephone. A horn of the "exponential" type having an odd number of sound passages including an even number of re-entrant passages, a relatively large area mouth and gradual taper is used to acoustically amplify the transmitted sound with minimum added distortion and with minimum added background noise and to effectively transfer the amplified sound to a telephone handset at a position removed from the horn mouth. Walls within the horn form sound passages of gradually decreasing cross-section which extend from the mouth to the tail of the horn, where an easy connect/disconnect acoustic coupling with the microphone of the telephone handset is provided. The tail of the horn is provided with an acoustical coupler which is shaped to transfer the amplified sound to the microphone of the telephone handset with minimum loss. This acoustic coupling is established when the telephone handset is in place on the telephone adapter. A conventional earphone transducer, an audio amplifier, and a loudspeaker in its separate housing are used to make audible the sound received via the telephone earphone.</p> |
