If you wake up one morning or notice that you hear little or no sounds during the day, for example when talking on the phone, there may be several reasons for this. While it may be a problem that can be fixed as easily as earwax, you may also be faced with a condition called sudden hearing loss that requires urgent treatment. We recommend that you consult an otolaryngologist as soon as possible.

 

Source:  http://www.kbb.org.tr