When two muscles (the tensor tympani muscle and the stapedius muscle) attached to the ossicles in the middle ear contract, the movement of the ossicles becomes much more rigid, greatly diminishing sound conduction to the inner ear. A response called the attenuation reflex causes these muscles to contract in response to a loud sound. The attenuation protects the inner ear from sounds at high intensities that would otherwise damage it. Since the reflex has a delay of 50-100 msec, it does not provide much protection for very sudden loud sounds. Therefore care must always be taken to avoid or minimize the exposure of loud noise to the ears.

Hearing loss can either be congenital (may be caused by hereditary factors or by medical conditions suffered by a fetus) or acquired (if it happens after birth). Acquired hearing loss in adults can be due to various causes, including natural ageing process, exposure to loud noise, disease, toxic mediation, ear infections, physical injury and a build-up of earwax.

It is advisable to consult a licensed medical professional or audiologist who will properly assess your hearing ability. People with hearing loss usually have a reduced ability to communicate as they find speech harder to follow and ask for repetitions. They might be complained about how loud they listen to the television or stereo. However, there are many other signs of hearing loss, and if it is suspected, make sure that diagnosis is performed as soon as possible and proper treatment is received  to ensure that it is not a symptom of another disease or ailment. 

There is a range of analogue and digital hearing aids available to suit individual needs and pockets. The different types of hearing aids include:

Behind-the-Ear (BTE) –attached to an ear mould and fits behind the ear of the wearer.

In the Ear (ITE) – customized to fit into the ear of the wearer.

In the Canal (ITC) and Completely in the Canal (CIC) - the whole hearing aid is fit into the ear canal. CICs are extremely tiny in size and are almost invisible.

Body-worn hearing aids - These aids require an external box to be worn by the user. The user wears an ear piece that is connected to the box by a wire.

Disposable hearing aids with built-in battery are also available. After certain amount of time usage, the user simply replaces the whole aid.

Potential risk is inherent in any surgery involving the use of general anaesthesia. Nevertheless, the surgical risks for cochlear implantation are minimal. A lot of patients require only a one-day hospital stay and have no surgical complications.

No, the design of the cochlear implants has changed relatively little for the past few decades. The implanted device is designed to last a lifetime. However, the externally worn speech processor, which converts sound into code and transmit the information to an internal unit, relies on software that can be upgraded as technology improves.