People have Outer Ears of different shapes, sizes and angles. Are they only cosmetic appendages, a mantlepiece to rest the spectacles, mask etc or is there a deeper meaning to their existance?
The outer ear comprises of a resonant cavity called the concha (pronounced Kawng.kuh). The word is derived from the latin word Conch (kawng), which is etymologically linked to the Sanskrit word "Shankh" both in its sound and meaning. Trivia : there are countless common words between Latin and Sanskrit leading to some fascinating theories about early human migration : for instance Dental & Dant, Serpant & Sarp, Ignis & Agni.....) . It's a fascinating rabbit hole to dive in, but let me not digress.
When you blow in a Conch Shell (Shankh), the Air trapped inside is unable to escape and resonates at a set frequency.Just as the Shankh, the Concha in the outer ear is a resonant cavity which after picking up sound boosts the 4000 Hz component and sends it along the ear canal to the ear drum. This makes human ears more sensitive to hearing sounds at high frequencies, such as a writhing snake, a feature which is an evolutionary advantage and has helped humans keep safe.
Image : Getty Images, Creatives Common Licence
The big flap which houses the Concha is called the Pinna. The bigger the Pinna, the more sound one can catch and hear. No wonder when people can't hear very well they like to cup their ears to artificially make them bigger. In real world scenario though the ear size will only make a small difference in overall loudness of sound detected.
Image by Alexander Krivitskiy
The third function of the outer ear is Sound Localisation. People generally identify the direction of any given sound based on the side they hear it louder. For instance sound coming from your right will be heard louder in the right ear than the left. Not only that, it will also reach the brain faster from the right hearing nerve because it hits the right ear first. Hence, we have intensity cues (loudness) and temporal cues (speed or timing) which help us in identifying the direction of sound.
Sound from multiple sources Photo by Alexandre Debiève on Unsplash
However this strategy isn’t fool proof when both ears get the sound at the same time and intensity, such as when sounds come from the front, back, above or below. Here the brain depends on the services of the outer ear. When standing on a first floor balcony, it will be the Pinna that will help you identify whether to look up or down in response to a sound you might have heard.
In a nutshell, the outer ear collects sounds, makes some of it louder because of the resonance in the Concha, and helps identify direction of sounds coming from the front, back, above or below.
Commonest concern with the Outer Ear.
Lucky for us problems with the outer ear are rare, and if at all, can be mostly treated with medication. One of the commonest problems that can lead to some sort of dysfunction is ear wax obstructing the passage of sound.
The ear canal is a cavity lined by skin, which is an extension of the skin on the face and the scalp. People who have oily skin on the face, generally also secrete more ear wax in the ear canal. People who have dry skin type, secrete less wax in the ears (commonest symptom: itchy ear). Wax keeps the ear canal lubricated. Now just as your nail grows from the back of the finger towards outside (proximal to distal), just like that the skin on the ear canal grows from inside (near the ear drum) towards the outside (towards the pinna).
The skin in the ear canal grows towards outside, similar to how the nails grow. Photo by Juan Salamanca
Once it reaches the outer concha, it dries out and sheds off, thus taking the dried wax along with it. This is why most people never ever need to have their ears cleaned. There is an inbuilt self cleaning mechanism.
For the rest, there are two big reasons why one may get wax occluding the canal. One is increased production : people with really oily skin produce so much wax that the oils mix up with the dead skin debris while still deep in the ear and form a clump that occludes the system. The second is when one, in an attempt to clear out the wax pushes it back instead.
The use of Presser for putting gunpowder firmly into place. Ear buds do exactly that. Image from the Encyclopedia of early firearms by David Darling https://www.daviddarling.info/encyclopedia_of_history/F/firearms_early_artillery.html
The Cue Tip performs the same miniaturised process that was used by early militaries 300 years ago to pack gun powder and cannon ball in a canon, yet there is a perception that the cotton covered blob may somehow grab an oily mass from a narrow canal and pull it out.
How does Indoor plumbing contribute to Ear Wax Occlusion? Well, all through the history of mankind if humans needed to take a bath, they would do so by jumping in a body of water, like a pond, river, sea or ocean. This would mean the head would be submerged into water, which would find its way in the ear canal and wash/clean it up.
Because of indoor plumbing, most baths are either through the bucket or the shower and in both cases the ear never gets cleaned from the inside. To further complicate this, most people I meet have a misplaced fear of water entering the ears. One should definitely avoid water entry in the ear if someone has a hole in the ear drum (perforated tympanic membrane), which is a case with a very small minority of people who have ear infections. The vast majority should have no problem with water entering the ear. (If you are in doubt about your ear health, ask a specialist to check this for you.) Since Water repels oil, it flushes out the oily ear wax out of the ear, unless the wax has been present for a long time and has dried up to a lump.
Submerging head under water clears out the ear wax. Photo by Juan Salamanca
Solution : When using the shower, it is a good idea to let water enter your ears, perhaps by tilting the neck slightly ( About 15-20 degrees) when washing the head so water can wash the ear from the inside. This way excess wax will wash out as it is formed. However if one is doing it after a very long time, do have the ears examined by an Ear Expert to make sure there is no ear drum perforation or clumps of dried ear wax which may swell up because of water entry (just as dried vegetables in your packed pasta swell up when you add water to them). That is a rare occurance though.