Final answer:
Post-lingual onset of hearing loss is hearing loss that occurs after language has been acquired, often due to factors like noise, aging, or infections. It can be measured in phons, with severities of 40 or 60 phons affecting the ability to hear conversations at various levels. Presbycusis refers to age-related hearing loss, predominantly of higher frequencies, while sensorineural hearing loss involves neural signal transmission failures.
Step-by-step explanation:
Post-lingual onset of hearing loss refers to hearing loss that occurs after an individual has acquired language skills, which typically happens after the age of five. This type of hearing loss can be caused by various factors, including noise exposure, aging, infections, and certain medical conditions like Ménière's disease. Unlike congenital deafness, individuals with post-lingual hearing loss have developed the ability to speak and understand verbal language before losing their hearing.
Hearing loss can be measured in units called phons. A 40-phon hearing loss at all frequencies may still permit understanding of conversation, though it will be quieter. However, with a 60-phon loss, understanding speech becomes challenging, especially at higher frequencies which affects clarity, hence making it difficult to discern female voices or enjoy music. This higher-frequency loss is associated with a condition called presbycusis, which is the gradual loss of hearing that occurs as individuals age.
Sensorineural hearing loss, another type of hearing impairment, involves failure to transmit neural signals from the cochlea to the brain and may not benefit from conventional hearing aids; though, a cochlear implant might be an option for some individuals. Conductive hearing loss, on the other hand, is due to problems in delivering sound energy to the cochlea, such as blockages or fluid in the ear.