Outer ear
Encyclopedia
The outer ear is the external portion of the ear
, which consists of the pinna, concha
, and external auditory meatus. It gathers sound energy and focuses it on the eardrum (tympanic membrane). One consequence of the configuration of the external ear is to selectively boost the sound pressure
30- to 100-fold for frequencies around 3 kHz. This amplification makes humans most sensitive to frequencies in this range - and also explains why they are particularly prone to acoustical injury and hearing loss near this frequency. Most human speech sounds are also distributed in the bandwidth around 3 kHz.
s can move the pinna (with the auriculares muscles) in order to focus their hearing in a certain direction in much the same way that they can turn their eye
s. Most humans, unlike most other mammals, do not have this ability.
s move into the ear canal
, a simple tube running through the middle ear
. This tube leads inward from the bottom of the auricula and conducts the vibrations to the tympanic cavity and amplifies frequencies in the range 3 kHz to 12 kHz.
Ear
The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....
, which consists of the pinna, concha
Concha
Concha can refer to:* The bowl-shaped part of the pinna nearest the ear canal* Concha or Concho, a round decorative piece of metal seen on a western saddle and other horse equipment descended from the Spanish tradition....
, and external auditory meatus. It gathers sound energy and focuses it on the eardrum (tympanic membrane). One consequence of the configuration of the external ear is to selectively boost the sound pressure
Sound pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient atmospheric pressure caused by a sound wave. Sound pressure can be measured using a microphone in air and a hydrophone in water...
30- to 100-fold for frequencies around 3 kHz. This amplification makes humans most sensitive to frequencies in this range - and also explains why they are particularly prone to acoustical injury and hearing loss near this frequency. Most human speech sounds are also distributed in the bandwidth around 3 kHz.
Pinna, or auricle
The visible part is called the pinna. It is composed of a thin plate of yellow elastic cartilage, covered with integument, and connected to the surrounding parts by ligaments and muscles; and to the commencement of the external acoustic meatus by fibrous tissue. Many mammalMammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s can move the pinna (with the auriculares muscles) in order to focus their hearing in a certain direction in much the same way that they can turn their eye
Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
s. Most humans, unlike most other mammals, do not have this ability.
Ear canal, or external auditory meatus
From the pinna the sound pressure waveWave
In physics, a wave is a disturbance that travels through space and time, accompanied by the transfer of energy.Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass...
s move into the ear canal
Ear canal
The ear canal , is a tube running from the outer ear to the middle ear. The human ear canal extends from the pinna to the eardrum and is about 35 mm in length and 5 to 10 mm in diameter....
, a simple tube running through the middle ear
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...
. This tube leads inward from the bottom of the auricula and conducts the vibrations to the tympanic cavity and amplifies frequencies in the range 3 kHz to 12 kHz.