The Lac du Bonnet Wildlife Association has conducted a series of sound testing in the surrounding area to determine the effects of noise on the area.
Decibels levels were recorded to measure the relative loudness or level of a sound. Each set of 10 dB represents a doubling of the subjective impression of the loudness of the sound. Many of these tests were witnessed by landowners from the surrounding area that were interested in participating as well as members of the RM council.
The closest property to the sight is located 1.45 km away and is where the highest sound levels were recorded. Background sound at that area was recorded as an average of 37.1 decibels (dBA). The average level recorded during rifle testing was 41.6 dBA, an increase of only 4.5 dBA over background noise.
To put this into perspective a soft whisper at 5 feet away is 34 dBA; conversational speech 60 dBA, city traffic 92 dBA; a chainsaw, leaf blower, or snowmobile 106 to 115 dBA; and a jet engine 140 dBA. A level of 60-65 dBA is generally considered the threshold for annoyance or limited community reaction.
At the closest property to the site, an increase of 18.4 dBA would be required to reach the threshold for annoyance. This correlates to the sound of the rifle shots needing to be 3.580 times louder to reach the level for annoyance. Even when a 5 dBA penalty is applied to compensate for the sudden quick impulse sounds made by a rifle, the sound would need to increase 13.4 dBA or be 2.532 times louder to reach annoyance.
Sound levels from shotgun testing were recorded at slightly lower levels. The tests were taken in a variety of wind and weather conditions and at different times of the year when the leaves were both on and off the trees of the surrounding forest. During the testing, some shots taken could not be heard by most of the people present. Several test shots had to be delayed due to background noises from the nearby highways, birds, and wind which
would drown out the firearm sound making it undetectable.
The construction of backstops, berms, range covers, and other construction at the site of the
Outdoor EducationCentre is also expected to further reduce the sounds heard by our neighbours.