People hear sounds when sound waves travel through the air to the ears. The visible outer ear is only a small part of the organ and hearing, and parts of the inner ear transmit the sound waves to the brain.Know More
The external part of the ear is made up of the auricle and the external auditory canal. The auricle has a slightly cupped shape to allow it to collect sound waves and direct them into the auditory canal. The auditory canal then passes sound waves to the middle ear.
The middle ear is separated from the auditory canal by the eardrum, or tympanic membrane. The tympanic cavity contains three tiny, movable bones: the hammer, the anvil and the stirrup. Sound waves pass through the eardrum, across the three bones and into the inner ear.
The inner ear consists of a bony labyrinth and a membranous labyrinth. A fluid known as perilymph separates the two. Sound waves travel through the perilymph to fibers in the basilar membrane in the cochlea. These fibers set up a vibration in the specialized hair cells that make up the organ of Corti, which is the organ of hearing. The vibrations of the hair cells stimulate the nerves attached to them. These nerves in turn send messages through the auditory nerve to the temporal lobe, which is the brain's center of hearing.Learn more about Human Anatomy
Bowel sounds are often heard as food moves through the intestines because the intestines are hollow and the noise from this movement can echo throughout the abdomen, according to MedlinePlus. Growling noises can be heard coming from the stomach after eating as well. The Mayo Clinic explains, as hunger triggers muscle contractions and the release of acids and digestive fluids that causes the audible rumbling noise.Full Answer >
A turtle's ears are flat against the head, but a turtle can hear as well as a cat. Turtles have the same inner ear mechanisms that other animals do, and they also have an auditory nerve and the brain center required for hearing.Full Answer >
Technically, snakes do not hear because they don't have ears. Specifically, they are deaf to sounds that travel through the air. However, they do manage to sense what would be sounds to animals with ears. However, the snake does have an inner ear.Full Answer >
Cartilage, which makes up most of ears and noses, continues to grow even after other parts of the human body, even bone, stop growing, according to Arthur Perry, M.D., of the Dr. Oz Show, although other experts disagree. The force of gravity also works on earlobes to cause elongation.Full Answer >