Book on noise effects on man covering audiometry, aural reflex, hearing damage risk, physiological responses, motor performance and speech communication

The effects of noise on man.

Throughout the Appalachian Mountain chain, entrepreneurs have capitalized on the outdoor sporting experience.  Both summer and winter sports such as fly fishing, hiking, skiing and snowboarding are very popular. One popular emerging activity is skeet, trap, and sporting clays shooting.  Major tourist enterprises are developing this opportunity for both tourists and the local residents.  To meet the increasing demand, ranges are being constructed throughout the region from Alabama to Maine.  Within North Carolina that are approximately 12 ranges, with an additional 10 in east Tennessee. Although these activities have had few opponents, sporting clays establishments have received an insignificant number of complaints that the noise level is above the noxious level.  A research experiment was designed to test noise levels at one sporting clays course situated near a vacation resort. The first phase of this experiment determined that the noise levels at the source from 12 and 20 gauge shotguns were insignificant. The allowable rounds used are the standard reduced load target load. At the source there was a significant difference between trap (85.85 dBA) and skeet (74.95 dBA). At the closest guest location (second phase) 333 samples were taken between August 2015 and March 2016.  The noise level averaged 53.7 dBA (σ = 7.43dBA). During the third phase (January to March 2016) 44 samples were obtained at the main resort lodging site.  At Site 2 the noise level averaged 31.9 dBA (σ = 5.45).  The fourth and final phase of this study was to determine the noise levels at the closest guest location for each of the 12 sporting clays stations.  Ninety-six samples (8 per station) were collected in October 2016. The average noise level was 53.0 dBA (σ 4.19 dBA). An analysis at the statistical confidence level of 97.5% was conducted.  First all stations were analyzed in a pairwise comparison analysis.  Stations that were not significantly different from one another were combined.  Thus the 12 stations were reduced to three combined stations.  The analysis determined that the noise level from stations 1 through 5 (48.9dBA, σ =1.50 dBA) was significantly lower than from the other stations.  Next loudest was the combinations of stations 6, 7, 10, and 11 (54.1 dBA, σ = 1.69). The last loudest combination was stations 8, 9, and 12 (58.6 dBA, σ = 1.50 dDA).  Thus there was a difference of 9.7 dBA between the lowest and the loudest station.  Since every 5 dBA difference equates to 2 to 3 times louder, depending on frequency, the loudest station is approximately 4 to 6 times louder that the lowest noise level.  However, all stations are below the OSHA Standard.  With an annoyance level (60.0 dBA) for the guest activity, the gunshots are less than the nuisance level and significantly less than the permissible level. The few complaints about the noise levels are not supported by the noise level data. A logical conclusion is that the objection is the act of shooting and not the noise level of the shotgun’s sharp or impact report. Potential solutions might be to examine stations 8, 9, and 12 and considering possible relocation, orientation, or emplacement of a thick tree barrier to absorb the reports. Regression analysis was used to develop a highly significant model to predict noise levels with the variables collected. However, this will not solve the complaints from those who object to reports under any circumstance.

http://watsonojs.binghamton.edu/index.php/iser/article/download/69/pdf_30

Acceptable Noise Levels for Typical Outdoor Leisure Activities

Effects on human vary between uniform and time-varying traffic noise with the same equivalent sound level. Firstly, the subjective evaluation experiment of time-varying traffic noise is designed and implemented in this paper to get truthful data. Secondly, taking the gender, employment and mood factors into account, some conclusions about the effects of traffic noise with different time-varying characteristics on human are obtained based on the test results. Then the paper defines the disturbance degree of traffic noise on human as the subjective indicator of noise evaluation, represented by L m . Finally, taking multiple existing noise indicators as inputs and L m as output, three mathematical models are established using multiple regression, stepwise regression and artificial neural network analysis respectively.

Kelli Sprague

Papers

Continuous exposure to noisy work environments does affect preferred leisure noise levels