Final answer:
Congenital deafness is hearing loss present at birth and can have genetic or environmental causes. There are types of hearing loss, such as conductive and sensorineural, with the latter potentially treatable by cochlear implants in some cases.
Step-by-step explanation:
The hearing loss present at birth, which may or may not be associated with familial hearing loss, is known as congenital deafness. This condition can result from various causes including genetic factors and in utero environmental exposures. It's also important to differentiate between the types of hearing loss, such as conductive hearing loss and sensorineural hearing loss. Conductive hearing loss occurs when there are problems with conducting sound waves through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles), while sensorineural hearing loss is due to damage to the inner ear (cochlea), the nerve pathways from the inner ear to the brain, or a combination of both. Hearing loss at 4000 Hz, typically caused by noise exposure such as a cap gun, is an example of how environmental factors can contribute to hearing loss. Another form is presbycusis, which is age-related hearing loss affecting higher frequencies. In some cases, treatments such as cochlear implants may be an option for those with sensorineural hearing loss.