| 摘要 |
An infrared assistive listening system capable of enhanced performance in medium-sized locations, such as courtrooms, classrooms, and conference rooms, is realized by a system comprising a pressure zone microphone capable of picking up distant speakers, a high-gain pre-amplifier, an equalization and pre-emphasis circuit, an automatic gain control and limiting circuit, a mute feature capable of remote activation, an FM modulator, a pulse width modulator, and a high-power single front throw infrared emitter. Another embodiment of the invention employs a multi-directional infrared emitter array in conjunction with the single front throw emitter. |
