 Dear students, in this topic we shall discuss the physiological anatomy of mammalian ear. Ear is the organ of hearing that detects sound in particular frequency range. An ear can detect sound frequencies lying between 20 to 20,000 Hz. The ear of the mammals has three major duetions. Number one, the external ear. Number two, the middle ear. And the third duetion is the inner ear. These three parts of ear are designed to conduct sound waves through three different types of media. External ear receives sound waves from the ear. Second, the bone is the middle ear, and the sound waves in the middle ear are the vibrations of the bones. The second medium is the bone. And third, when sound waves reach the inner ear, there is fluid in the cochlea and the fluid is the vibration. As a result, sound is transformed into fluid medium. In this way, the structure of the ear is passed through three media and then the sound is perceived by the mammals. Now we shall discuss the three components of ear in detail. First we shall discuss the external ear. The external ear includes three main parts. First is the pinna. It is also called oracle. This is the pinna. Then there is an external auditory metis. The canal in the ear is called the ear canal or external auditory metis. The third part is the tamponic membrane, which is called the ear drum or the ear canal. These structures act as a funnel that collects the sound waves from the environment. As a result, these structures amplify the sound and concentrate the sound on to the ear drum which is the last part of the external ear. All the sound is concentrated on it as a result that vibrates. Now we shall discuss the middle ear. The middle ear contains three auditory ossicles that is three small bones of the ear. First is the malleus. Second is the incus. And third is the steps. These three bones are arranged in a series. On one side, malleus is attached to the ear drum while on the other side, steps is attached to the oval window of cochlea. The middle ear receives sound waves as vibrations from the ear drum and transmits them to the oval window of cochlea passing through the three bones of middle ear. The middle ear also amplifies sound waves. In the middle ear, the amplification of sound waves is approximately 20-fold or more than this. Now we shall discuss the inner ear. Inner ear consists of a bony labyrinth which is filled with parylymph. It has an oval window and a round window. Oval window receives the sound vibrations through steps. Bony labyrinth K under there is the membranous labyrinth. This membranous labyrinth is filled with endolymph. The membranous labyrinth consists of three parts. First, it contains three semi-circular canals. And secondly, it contains the vestibules that is secular and eutricles. These two parts are vestibular apparatus and sense of equilibrium is involved. The third part is cochlea which is involved in hearing. Cochlea is the part which transduces the mechanical energy of sound vibrations and converts them into electrical nerve impulses.