While sonus complete australia is typically associated with the elderly, people of all ages can suffer with this condition. Some of the common causes are excess accumulation of wax in the ear (Cerumen), or any infection to the external ear, pressure changes experience by the tympanic membrane (Very common during a journey to high altitudes or a tunnel), Otitis media, or any ear infection, when the Eustachian tube is blocked etc. The next two categories are the ultra high range of sonus complete australiaes namely severe and profound.
https://walkinghealth.org/sonus-complete-australia/