NCO Promotion Minimums. At the NCO grades of E-4 and E-5 the process becomes competitive, meaning there are only so many openings available. At minimum you still have to meet time-in-service and time-in-grade requirements. To make E-4 requires at least 12 months in the service and 8 months as an E-3.To make sergeant (E-5) requires at least 24 months in the service and 12 months as an E4-.arine Corps Enlisted Ranks. Marine Corps sergeants have a pay grade of E-5, with the E standing for enlisted.. To make sergeant you must climb through the lower ranks: Private (E-1), private first class (E-2), lance corporal (E-3) and corporal (E-4).
The Outer Ear. The outer ear consists of the pinna (the part we can see), and the ear canal down to the eardrum. This part of the ear has several functions relating to hearing. The pinna acts like a funnel; it collects sounds and directs them down our ear canal.
The anatomy of the ear can be a little confusing, especially since the ear is responsible not only for hearing, but also for balance. There are three components to the ear: the outer ear, the middle ear and the inner ear. All three are involved in hearing but only the inner ear is responsible for balance.The outer ear is composed of the pinna, or ear lobe, and the external auditory canal.Both structures funnel sound waves towards the ear drum or tympanic membrane allowing it to vibrate. The pinna is also responsible for protecting the ear drum from damage. Modified sweat glands in the ear canal form ear wax.he anatomy of the ear can be a little confusing, especially since the ear is responsible not only for hearing, but also for balance. There are three components to the ear: the outer ear, the middle ear and the inner ear. All three are involved in hearing but only the inner ear is responsible for balance.