多少db算噪音..对于人耳能听到的声音范围一般在**20-20kHz**频率范围内,大约是从140 dB SPL(SPL代表sound pressure level,即声压级)开始到颅骨所能达到的上限约可承受90 D
Decibel Meter is an app intended for objective, real-time measurement of ambient noise and sound levels. It is intended for noise pollution control with the aim…
声功率级（Sound Pressure Level，SPL）是表示声音强度的一种物理量。它的单位是分贝（dB），并且是以单位声功率为参考值的相对量。因此，要求出四个声功率级分别为8，90，95，97dB的声源的总声功率级，可以使用以下公式：总声功率级 = 10 * log10(声功率级1^2 + 声功率级2^2 + 声功率级3^...
*** Decibel Level Table*** 0-20dB is very quiet and almost impossible to feel 20-40dB Quiet, Soft Talk 40-60dB Normal, ordinary indoor talking 60-70dB noise, sp…
耳放如果自己做的话, 是用不了 2000 人民币的。 理论THD <0.001% (-100dB) 的八管耳放 理论THD <0.001% (-100dB) 的八管耳放 Harmonic Frequency Fourier Normalized Phase Normalized Number [Hz] Component Component [degree] Phase [deg] 1 1.000e+03 4.138e+00 1.000e+00 0.06° 0.00° ...
Sound Level Comparison Chart Table of sound level dependence and the change of the respective ratio to subjective loudness (volume), objective sound pressure (voltage), and sound intensity (acoustic power). How many decibels (dB) level is double, half, or four times as loud? How many dB to...
Sound pressure level (dB) of broadcasted calls measured at 1.5 m distance from the loudspeaker in a sound proof chamber.Peter, MaciejJulia, FischerKurt, Hammerschmidt
Incidentally, the sound pressure p doesn't decrease with the square of the distance from the sound source (1/r²). This is an often-told and believed wrong tale.Sound Level Comparison Chart with FactorTable of sound level dependence and the change of the respective factor to subjective ...
This app turns your iOS device into a professional sound level meter, detects harmful environmental noises, and helps protect your hearing and health. "Decibel X" is one of very few noise meter apps on the market that has highly reliable, pre-calibrated measurements and supports dBA, dBC. It...
aUse of Subcontractors 对转承包商的用途[translate] a各相导线 Each wire[translate] alegislator 立法者[translate] a泡温泉在台山 Soaks the hot spring in Taishan[translate] aSound level should be not more than 60 db 声音强度应该是不超过60 db[translate]...