吸声尖劈高频声学特性比较评价法

Comparative evaluation method for high-frequency acoustic characteristics of sound absorbing wedges

吸声尖劈的声学性能直接影响消声室自由声场空间范围的参数结果,然而驻波比法和传递函数法无法评价吸声尖劈的高频声学特性,为此提出一种自由声场空间范围比较评价法,实现吸声尖劈高频声学特性的评价。该方法建立在已知自由声场空间范围的消声室环境基础上(自由声场空间范围定义为参考值),将消声室内足够面积的尖劈替换为被校准的吸声尖劈,测量当前轴向的自由场空间范围结果并与参考值进行比较,得到被校准吸声尖劈与参考尖劈的声学特性差异,实验结果表明该方法有效可行。此外,设计3组实验对该方法进行优化:在实际应用中传声器朝向声源测量、声压级结果需进行声衰减补偿,消声室内地网铺设吸声材料可有效降低实验误差。

The acoustic performance of sound absorbing wedges directly affects the parameter results of the free sound field spatial range of anechoic chamber.However,the standing wave ratio method and the transfer function method cannot evaluate the high frequency acoustic characteristics of the sound absorbing wedges.To this end,a free sound field spatial range comparative evaluation method is proposed to evaluate the high frequency acoustic characteristics of the sound absorption wedges.The method is based on the anechoic chamber environment of the known free sound field spatial range(the free field domain is defined as the reference value),and the sufficient area of the anechoic chamber is replaced with the calibrated sound absorbing wedges.Measuring the current axial free field domain result and comparing it with the reference value to obtain the difference in acoustic characteristics between the calibrated sound absorbing wedges and the reference wedges.Experimental results show that the method is effective and feasible.In addition,three sets of experiments are designed to optimize the method.In practical applications,the microphone towards the sound source to measures the sound pressure level,sound pressure level results require acoustic attenuation compensation,the sound absorbing material is spread in the grounding net,which can effectively reduce the experimental error.