传声器风罩防风性能测试影响因素研究

Investigation into the Factors Affecting Windproof Performance Testing of Microphone Windscreens

传声器风罩作为声探测系统中的重要组成部分,其主要功能是使测试结果免受外界风噪声的干扰,确保在户外测量时能够获得准确、可靠的数据,传声器风罩防风性能的好坏会直接影响测试结果,因此,研究风罩防风性能的测试方法及影响测试结果的因素具有重要意义。用相同风速下,传声器佩戴风罩前后的1/3倍频程差来表征风罩的防风性能,采用在声学风洞中测试的方法研究测点位置及背景噪声对风罩防风性能测量的影响。研究结果表明,由于流场边缘湍流度的增加,在风口试验段边缘的测试结果比试验段中心区域的测试结果高2.0~32.8 dB,因此,在选择测点位置时,应避免将风口边缘的位置作为测试位置;此外,通过在风洞中布置声源改变风洞的背景噪声,对比测试结果发现,在背景噪声频带声压级满足低于频带测量值至少7 dB时,背景噪声不影响测试结果,因此,在衡量背景噪声是否满足风罩防风性能的测试要求时,应用1/3倍频带声压级来衡量且满足频带测量值大于背景噪声至少7 dB的要求。

Microphone windscreens,pivotal in acoustic detection systems,serve to mitigate wind noise interference in outdoor testing,ensuring accurate and reliable data.The windproof efficacy of these windscreens is critical to test outcomes.This study focuses on the methodologies for assessing windscreen windproof performance and the factors influencing these results.The windscreen's windproof capability is quantified using the 1/3 octave frequency difference pre-and post-windscreen application at a constant wind speed.The impacts of measuring point position and background noise on windproof performance are explored.Results reveal that the turbulence increase at the flow field edge leads to test results at the wind tunnel inlet's edge being 2.0 to 32.8 dB higher than those in the central region.Thus,it is advisable to avoid the tunnel inlet's edge for test positioning.Additionally,altering the wind tunnel's background noise with sound sources demonstrated that test outcomes remain unaffected by background noise if the 1/3 octave band sound pressure level is at least 7 dB lower than the measurement band's sound pressure level.Consequently,to determine if background noise meets testing standards,the 1/3 octave band sound pressure level should be used,ensuring it is at least 7 dB lower than the measured band's level.