Here is an amazing collection of Number Facts about your ear!
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Numerical Facts about Parts of Ear
| Surface area of the tympanic membrane | 85mm2 |
| Length of the Eustachian tube | 3.5 to 3.9 cm |
| Number of hair cells in cochlea | 3,500 inner hair cells; 12,000 outer hair cells |
| Number of fibers in auditory nerve | 30,000 |
| Length of auditory nerve | 2.5 cm |
| Number of neurons in cochlear nuclei | 8,800 |
| Number of neurons in inferior colliculus | 392,000 |
| Number of neurons in medial geniculate body | 570,000 |
| Number of neurons in auditory cortex | 100,000,000 |
| Length of external auditory meatus | 2.7 cm |
| Diameter of external auditory meatus | 0.7 cm |
| Weight of Malleus | 23 mg |
| Length of Malleus | 8-9 mm |
| Weight of Incus | 30 mg |
| Dimensions of Incus | 5 mm by 7 mm |
| Weight of stapes | 3-4 mg |
| Dimensions of stapes | 3.5 mm high, 3 mm long,1.4 mm wide |
| Length of cochlea | 3.5 cm |
| Width of cochlea | 1 cm |
Sound scale in Decibel Unit
| Soft whisper | 30 |
| Average home | 50 |
| Normal conversation | 66 |
| Busy traffic | 75 |
| Noisy Restaurant | 80 |
| Subway | 90 |
| Automobile horn | 120 |
| Discomfort | 120 |
| Pain threshold | 130 |
| Jet plane | 140 |
| Gunshot blast | 140 |
| Rocket launching pad | 180 |
Hearing Range of Various Animals
| Young adult human | 20 to 20,000 Hz |
| Elderly human | 50 to 8,000 Hz |
| Most sensitive range of human hearing | 1,000 to 4,000 Hz |
| Rat | 1,000 to 50,000 Hz |
| Cat | 100 to 60,000 Hz |
| Dolphin | 200 to 150,000 Hz |
| Elephant | 1 to 20,000 Hz |
| Goldfish | 5 to 2,000 Hz |
| Moth, noctuid | 1,000 to 240,000 Hz |
| Mouse | 1,000 to 100,000 Hz |
| Sea lion | 100 to 40,000 Hz |
