a-weighted sound level การใช้

• Standard guide for measurement of outdoor a - weighted sound levels
• All kinds of methods measuring noise have been produced and a - weighting sound level is extensively used as a kind of fundamental measure in all of the world
• An under estimation of the hearing effects by the low frequency noise could be happened . that is to say , even if the a - weight sound level is small , the low frequency noise may annoy to listener by the different ways from the high frequency noise . so it is necessary to understand psychoacoustics in order to make noise quality evaluations that match the subjective experience of the purchaser