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The extrinsic auricular muscles are the three muscles surrounding the auricula or outer ear: anterior auricular muscle; superior auricular muscle; posterior auricular muscle; The superior muscle is the largest of the three, followed by the posterior and the anterior. In some mammals these muscles can adjust the direction of the pinna.
Amplification of sound by the pinna, tympanic membrane and middle ear causes an increase in level of about 10 to 15 dB in a frequency range of 1.5 kHz to 7 kHz. This amplification is an important factor in inner ear trauma resulting from elevated sound levels .
The outer ear is the external portion of the ear and includes the fleshy visible auricle, the ear canal, and the outer layer of the eardrum (also called the tympanic membrane). [ 2 ] [ 3 ] The auricle consists of the curving outer rim called the helix , the inner curved rim called the antihelix , and opens into the ear canal.
Thus, a "positive" result indicates the healthy state, in contrast to many other medical tests. Therefore, some prefer to avoid using the terms "positive" or "negative", and simply state if the test was normal or abnormal. For example: "Rinne's test was abnormal in the right ear, with bone conduction greater than air conduction".
The human auditory system has only limited possibilities to determine the distance of a sound source. In the close-up-range there are some indications for distance determination, such as extreme level differences (e.g. when whispering into one ear) or specific pinna (the visible part of the ear) resonances in the close-up range.
A single lesion on the front part of the ear is usually the initial sign of pseudocyst of the auricle. Pseudocysts of the auricle appear as flesh-colored, nontender, noninflammatory cystic lesions and progress gradually over a 4- to 12-week period. Their diameters range from 1 to 5 cm. Usually, the lesions start off soft and get firmer with time.
Now that the sun is at the height of its 11-year cycle, the increase in solar activity has more frequently fueled "space weather" that produces the right conditions for northern lights to flourish
The outer ear funnels sound vibrations to the eardrum, increasing the sound pressure in the middle frequency range. The middle-ear ossicles further amplify the vibration pressure roughly 20 times. The base of the stapes couples vibrations into the cochlea via the oval window , which vibrates the perilymph liquid (present throughout the inner ...