Sounds in poor visibility.
In regions of poor visibility such as fog or mist, the direction of sounds can be very difficult to identify.
One approach to improving you hearing is to try opening you mouth wide. Some times you can hear slightly better, if you then turn your head a few degrees from one side to the other you may get a better impression of the direction of a sound.
In very poor visibility I have done this on two fog signals and been able to put a position on the chart, which was remarkably accurate.
Of course, if your mouth is open wide, you can not be talking, so you will probably hear better anyway!
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