![]() ![]() Most modern and advanced sound level meters and sound analyzers will have A-,C-,Z- weightings. Measurements are displayed as dB(Z) or dBZ, or LZeq, LZFmax, LZE. This is often used in octave band analysis and for measuring environmental noise. The Z weighting is made with zero weighting for the human ear which covers flat frequency response of 8Hz to 20kHz (+/- 1.5dB). Measurements are displayed as dB(C) or dBC, LCeq, LCPeak, LCE. The C-weighted measurements is ideal for monitoring short spontaneous loud noises such as explosions, bangs, high power engines, explosions, etc. The C weighting are typically used for higher peak noise level measurements such as Peak Sound Pressure Measurements which referred as CPeak. This is the noise level of a rocket ship. Now, you’re basically talking about weaponized audio. 126+ dB: 125 decibels is where sound really begins to get painful. Aircraft takeoff, trains, and quite loudly concerts would fall to the 110+ decibel level. Measurements are usually displayed as dB(A) or dBA or as LAeq, LAFmax, LAE. 101-125 dB: 110 decibels and above is the level where other sounds can not truly be heard. The A weighted frequency curve is mandatory for environmental and industrial noise measurement as well as evaluating potential hearing damage and health effects of noise. (USA) require to at least include an A-weighting filter in sound level meters. International standards such as the IEC 61672 and ANSI S1.4. The A weighting filter covers the full noise frequency range from 20Hz to 20kHz. The A weighting is the most commonly used frequency response and best reflects the sensitivity of the human ear to noise. The overnight A-weighted Leq of 53.6 dBA was well above World Health Organization recommendations overnight C-weighted Leq was 63. Equivalent sound level (Leq) and sound peaks were reported for full and partial night periods. The screenshots below from ST-15D Sound Analyzer shows the Sound Pressure Level (SPL), with the maximum and minimum sound level (Lmax and Lmin) with a choice of A, C, and Z frequency weightings. Sound level was recorded every 10 seconds on A- and C-weighted decibel scales. There are 6 kinds of noise frequency weightings A-,B-,C-,D-,G- and Z-weightings.Ī-, C-, and Z-weightings are the most commonly used nowadays as defined in the sound level meter standards IEC 61672:2013, while B- and D- weightings are no longer mandatory to use. In order to represent the human hearing precisely, frequency weightings is used by putting more weight into some frequencies over others.ĭifferent noise frequency weightings contains different range of noise frequency related to the human ear. When measuring sound pressure level especially for potentially damaging noise levels at workplace, it is crucial that the sound level meter is able to accurately monitor noise as what the human ear actually hears. Z – Weighting The Importance of Frequency Weightings ![]()
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