A speaker in a signal?? What is it used for? Any idea?

Date: 2005-12-16
Owner: Jimmy Jose
Size:
Full size: 768x1024

Photo Properties
Summary  Details
Make Canon Model Canon PowerShot A95
Aperture Value f/3.2 Color Space sRGB
Flash Compulsory Flash Metering Mode Multi-Segment
Shutter Speed Value 1/500 sec Digital Zoom Ratio 1
Date/Time 2005 Dec 16 11:45:49 +0000