>Perhaps others have had more recent experience. Modern day aids have
>excellent volume and output controls making the possibility of increased
>loss secondary to proper hearing aid use very unlikely. However, if you
>wear an aid around hazardous noise, the use of the aid will increase the
>risk of a noise induced hearing loss.
Assuming the aid has some form of output limiting that is set at a
reasonable level and the vent isn't too big the aid may actually
protect the user from excessive levels.