during cost analysis you will also compare the proposed cost elements with i actual costs ii previous cost estimates for same or similar work iii other cost estimates iv independent government estimates and v forecasts of planned expenditures
How Decibels Apply to Music and Sound. In music, decibels are a measurement of Sound Pressure Level (SPL). When we say the speakers at a rock concert are playing at 110dB, what we really mean is that theyâre playing at 110dB SPL. Since the decibel is only a ratio, 110dB is actually a comparison to a different number: 0 SPL.
Sound pressure is measured in decibels (dB). Like a temperature scale, the decibel scale goes below zero. The average person can hear sounds down to about 0 dB, the level of rustling leaves. Some people with very good hearing can hear sounds down to -15 dB. If a sound reaches 85 dB or stronger, it can cause permanent damage to your hearing. The amount of time you listen to a sound affects how much damage it will cause. The quieter the sound, the longer you can listen to it safely.