A pinger, they are attached to nets at intervals which are set on the sea bed. It is used to keep dolphins away from the net by emitting a loud noise, too loud for humans to hear. Does it work well I didn't see any dolphins in the nets.
well buckleyman if that's your real name, I mean emitting at a frequency that is too high for humans to hear, other devices like this are dog whistles and plug in rodent deterrents.
It's hardly too loud for us to hear, is it? If so, have you got any rudimentary science on that to help my feeble brain understand?
ReplyDeletewell buckleyman if that's your real name, I mean emitting at a frequency that is too high for humans to hear, other devices like this are dog whistles and plug in rodent deterrents.
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