Defrag is a process that your computer does to sort all the information. Weird as it sounds, your computer sometimes pulls apart the pages of a file and puts them into different places on your hard drive. It leaves little notes on each sheet of paper to help it find where the next page in the file is located.
For humans, normal hearing is between â10 dB(HL) and 15 dB(HL) , although 0 dB from 250 Hz to 8 kHz is deemed to be 'average' normal hearing. Hearing thresholds of humans and other mammals can be found by using behavioural hearing tests or physiological tests.hey are not the same as equal-loudness contours, which are a set of curves representing equal loudness at different levels, as well as at the threshold of hearing, in absolute terms measured in dB SPL (sound pressure level).
Tweet. A decibel dB(A) is a unit of measurement that indicates how loud a sound is. Humans can hear sounds between 0 and 140 decibels. 0 decibel does not mean that there is no sound, merely that we cannot hear it.0 decibel is the so-called hearing threshold for the human ear.While we can hear more than 140 decibels, it is too painful for our ears and if you expose yourself to such a loud noise you are at extremely high risk of permanent damage to your hearing. The table blow shows how loud sound is. decibel dB(A) is a unit of measurement that indicates how loud a sound is. Humans can hear sounds between 0 and 140 decibels.