| 摘要 |
<p>A social alarm unit (10) monitors the safety and wellbeing of a client in their own home or a sheltered housing scheme. The social alarm unit (10) provides a speech communication path, such as over a public switch telephone network (PSTN), to an operator at a remote monitoring station or control centre when an alarm is triggered. The social alarm unit (10) selects between at least first and second communication modes (e.g. between a voice switched hands free mode and a tone switched half-duplex mode) depending on whether the alarm signal is received from a first trigger device (16) indicating that the client is close to the social alarm unit (10), or a second trigger device (32) indicating that the client is relatively distant from the social alarm unit (10). Speech communication is thus optimized to the expected position of the client and effects such as feedback are minimized.</p> |
