Criterion sound level

Criterion sound level A sound level of 90 decibels. 

Noise dose As defined by OSHA, e ratio, expressed as a percentage, of (1) the time integral, over a stated time or event, of the 0.6 power of the measured SLOW exponential time-averaged, squared, A-weighted sound pressure or (2) the product of the criterion duration (8 hours) and the 0.6 power of the squared sound pressure corresponding to the criterion sound level (90 dB). 

The sound levels emitted by the lifter zone change quite distinctly with variations in the running of the kiln and often correspond (with sometime lag) to the variations in the burning zone temperature. With a high fines content the sound levels, measured at a distance of 1 m from the cooler, may vary by about 20 dB (A). If these variations in sound are utilized as a criterion for kiln control, it should be remembered, however, that a high proportion of fine particles may, under certain raw material conditions, also be formed as a result of "over-burning" the clinker. 

The identified articles were screened by date, titles and abstracts of all retrieved references. The search was limited to articles, written in English, since 2004 to present. Electronic copies of articles were also identified. The articles retrieved for this review of the electronic databases were comphed with the following inclusion criterion relationship between sound levels and hearing loss. 

As regards the noise spectrum, the different situations can be analyzed ap proximately with NC (noise criterion) and NR (noise rating) curves (Fig. 9.6.3). NC and NR curves define the octave band limits of an acceptable back ground noise each of them is characterized by a number representing the sound pressure level at 1000 Hz. 

A more recent method of analysis uses the RC (room criterion) curves. In this case it must be calculated the arithmetical mean of sound pressure level at 500, 1000, and 2000 Hz. The obtained value identifies the specific RC curve. The noise is classified as rumbly (with excess of energy at low frequencies) if it is under 500 Hz and its sound pressure level exceeds the RC value by 5 or more dB. The noise is classified as hissy (with excess of energy at high frequencies) if it is over 500 Hz and its sound pressure level exceeds the RC value by 3 or more dB. 

Brain would seem to offer the potential for satisfying this criterion of sound experimental design. Brain is likely to have to perform similarly in all fishes, regardless of level of loco-... 

The exposure criterion used in these Regulations is the equivalent noise level over the working day or shift (Lep ci). Three actions levels are identified, the first action level is an lEP,d of 85 dB(A) when an employee has to be provided with hearing protection on request (Reg. 8(1)), the second action level is an exposure of 90dB(A) or more when hearing protection must be provided and worn (Reg. 8(2)) and the third level is the peak action level when a peak sound pressure level of 200 pascals occurs when hearing protection must, again, be provided and worn. 

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