The frequency theory aims to explain how the human brain experiences sound waves.
The frequency theory tries to explain how the brain experiences sound waves. While the frequency theory is primarily a physiological theory that seeks to explain how the anatomical structure of the ear is responsible for hearing, it is also a psychological theory that explores how the mind experiences sound.
Before the frequency theory can be fully understood, a brief description of the physiological structure of the ear is needed. Sound is picked up by the external ear, which is made up of the ear and the external auditory meatus. At this stage, the sound is an acoustic signal. Separating the outer and middle ear is the tympanic membrane or eardrum. As the acoustic signal enters the middle ear, the acoustic signal becomes mechanical due to the oscillating movement of the ossicular chain, which transmits the signal and increases the gain of the signal by approximately 22 decibels (dB) to the inner ear, where it will enter Sound. a fluid-filled cavity called the cochlea.
A basic idea of the physiological structure of the ear is necessary to understand the frequency theory.
The cochlea is located in the inner ear and consists of three fluid-filled chambers: the scala tympani, the scala vesibula, and the scala media. The scala media contains the organ of corti, known as the organ of hearing. The organ of corti houses hair cells that are excited when the signal enters the cochlea, which is now a hydraulic signal, and displaces fluid. As the fluid moves, it excites the hair cells, which in turn causes them to convert the hydraulic signal to a mechanical signal. This causes the auditory nerve to fire, sending an electrical signal to the brain’s auditory system, which the brain experiences as sound.
The cochlea is located in the inner ear and consists of three fluid-filled chambers: the scala tympani, the scala vesibula, and the scala media.
The frequency theory states that pitch is encoded by the firing frequency in the primary auditory fiber. The basilar membrane moves up and down due to the displacement of perilymphatic and endolymphatic fluid in the cochlea caused by each individual sine wave. The movement of the membrane causes the hair cells in the cochlea to become excited. Each nerve correlates to a specific frequency. Once this specific wave enters the cochlea, its frequency and intensity are sensitive to a specific nerve and cause that nerve to fire. The nerve cannot send another message until the message is sent and the nerve recovers. Each nerve fiber of the auditory nerve sends the information to the auditory cortex, where it collects the information and assembles it to perceive and interpret the auditory signal.
Disorders that affect the way the brain experiences auditory stimuli can cause hypersensitivity to some sounds.
The frequency theory, in the simplest terms, explains how the human brain basically experiences an auditory representational system. The frequency theory, in essence, states that humans do not actually experience sound waves, but rather vibrations in the auditory nerve, the frequencies of which are identical to the frequencies of sound waves reaching the ear.