| 摘要 |
A distributed self-adjusting loudspeaker system wherein each master loudspeaker unit includes self-contained circuitry (14) which senses ambient noise near each master loudspeaker (16) immediately prior to or during an announcement and automatically adjusts the amplified output level of the announcement at each individual master loudspeaker (16) and associated slave loudspeaker(s) (20), to compensate for the ambient noise levels. The system distributes a common audio signal to a plurality of locations subject to differing ambient noise levels and comprises a plurality of master loudspeaker units (16) each associated with a respective location, each of the units includes at least one loudspeaker and a microphone (18) for sensing noise at the respective location. The system includes single or multiple message inputs and a single central preamplification and conditioning circuit (10, 12) responsive to the signal input(s) for supplying the common signal input signal(s) to each of the master units. Each of the master units includes means, responsive to the respective noise sensing microphone (18), for adjusting relative gain applied to the message input signal(s) to a respective value corresponding to the local noise level and for applying the gain adjusted input signal to the respective loudspeaker. |
