Here Is Our Presentation Regarding Hearing Of Humans
Here is our presentation regarding hearing of humans and animals! Made by M- H Bil S S ll Z Bs
Human Hearing <ul><li>In a human, sound waves funnel into the ear via the external ear canal and hit the eardrum (tympanic membrane). </li></ul><ul><li>Us humans, we have a maximum aural range of 12 Hz under ideal laboratory conditions to 20,000 Hz in some individuals, but the range shrinks during our lifetime, usually beginning at around the age of 8 with the higher frequencies fading. </li></ul>Here is a diagram showing Tonaudiogram Here is a diagram of the difference between a dog ear and a human ear
Bats <ul><li>Bats require very sensitive hearing to compensate for their lack of visual stimuli, particularly in a hunting situation, and for navigation. Their hearing range is between 20 Hz and 120,000 Hz. </li></ul><ul><li>They locate their prey by means of echolocation. </li></ul><ul><li>A bat will produce a very loud, short sound and assess the echo when it bounces back. The type of insect and how big it is can be determined by the quality of the echo and time it takes for the echo to rebound; there are two types; constant frequency (CF), and frequency modulated (FM) calls that descend in pitch (Bennu 2001). </li></ul>
Dogs Hearing <ul><li>The hearing ability of a dog is dependent on its breed and age. </li></ul><ul><li>However, the range of hearing is approximately 40 Hz to 60,000 Hz,[ which is much greater than that of humans. </li></ul><ul><li>As with humans, some dog breeds become deafer with age </li></ul><ul><li>When dogs hear a sound, they will move their ears towards it, in order to gain maximised reception. In order to achieve this, the ears of a dog are controlled by at least 18 muscles. </li></ul>Here is a diagram of a dogs ear.
Dolphin <ul><li>Most dolphins have acute eyesight, both in and out of the water, and they can hear frequencies ten times or more above the upper limit of adult human hearing </li></ul><ul><li>Though they have a small ear opening on each side of their head, it is believed that hearing underwater is also if not exclusively done with the lower jaw, which conducts sound to the middle ear via a fat-filled cavity in the lower jaw bone. </li></ul><ul><li>Hearing is also used for echolocation, which all dolphins have. </li></ul><ul><li>This is similar to bats. </li></ul>