| 摘要 |
<p>A proximity warning system (10) is disposed in a sound protecting earmuff-type headset (16) or other means of providing acoustic ear protection. The ear protector prevents the user from hearing damage from high levels of ambient sound and would otherwise generally make the user unable to hear the sounds of approaching objects like vehicles (18) and machinery (20). However, an audio transducer (30) is provided in each ear shell (22) of the headset and is connected to a ranging device (32), which in the illustrated embodiment is an infrared ranging device which generates an alarm signal (40) upon the approach of an object within a predetermined critical alarm limit. A plurality of variable alarm signals can be provided to distinguish the direction, size and speed of the approaching object. In general, the ranging device may be optical, acoustic, thermal or electromagnetic.</p> |
