| 摘要 |
<p>A radio (10) measures and stores (16, 18) the ambient sound (or noise) level of its environment. When a message is received, the current noise (or sound) level is compared to a threshold (56). If the ambient noise level is such that an audible tone may not be heard by the radio user, a silent alert is automatically activated (62) regardless of whether the silent enunciator has been previously selected (enabled) by the radio user. In another aspect of the present invention, if the ambient noise level is such that an audible tone may be inappropriate (i.e., library, courtroom, or certain hospital areas), the silent alert is also automatically activated regardless of whether the silent enunciator is enabled so as not to disturb others.</p> |
