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).
If you are unable to detect sounds quieter than 90dB HL, the hearing loss is considered a profound hearing loss for those frequencies. If the average of the frequencies at 500Hz, 1000Hz, and 2000Hz is 90dB or higher, the person is considered deaf. A person who is hard of hearing can have a range of hearing loss from mild to severe. It should be noted that amplification technology is available for people with mild to profound hearing loss.