When a patient is looking for a specialist or a doctor regarding any of the specific conditions he is going through, it is essential to meet people who are well-versed and know everything about their situation.
ENT specialists in Gurgaon railway road are qualified to that level that they have studied internal and external structures of the ear, which helps them diagnose and treat the conditions related to ENT.
The pinna, which plays a role in the sound collection in some lower animals, does not function in human beings. The external auditory canal acts as a channel for the conduction of sounds from the auricle to the tympanic membrane and adds resonance to it, amplifying it by 10-12 decibels. Studying physiology is essential for the best ear doctor in Gurgaon because that will help with examinations and indirectly treating their patients in a good way.
PHYSIOLOGY OF HEARING
Sound is conducted from the external auditory canal through the tympanic membrane and ossicles to the cochlea, which is the sensory organ of hearing.
The hearing mechanism thus involves two components:
- The sound conducting mechanism (transmission).
- The perceptive neural mechanism
The sound conducting system extends from the external auditory canal to the cochlear fluids.
Physiology of the Conductive Mechanism
The functions of the ear include hearing and maintenance of balance.
The tympanic membrane and ossicles conduct the sound and increase its pressure before it transmits to the cochlea. This increase in sound pressure provided by the tympanic membrane and ossicles is necessary to overcome the impedance (resistance) to the sound transmission and is called the impedance matching function of the middle ear.
Impedance Matching of Middle Ear
Transmission of sound from the middle ear containing air to the cochlea containing fluid would have been problematic as this means sound information from perspective to liquid. Because of the difference in the acoustic properties of the two media, most of the sound reflected (impeded) would mean a loss of about 99.9 percent of acoustic energy. Nature provided a middle ear impedance matching system, which overcomes this resistance by increasing the sound pressure. The function is affected by the following.
- The sizeable effective surface area of the tympanic membrane (55 mm2) compared to the small surface area of the footplate of stapes (3.2 mm2) provides a magnification of about 17 times. It is called the hydraulic ratio.
The greater length of the handle of malleus compared to the long process of incus (1.3:1) called ossicular chain lever ratio also provides some gain in the transmission.
The two gains, the hydraulic and ossicular lever ratios (17 × 1.3 = 22), are known as the transformer ratio.
Middle ear functions as the sound pressure transformation mechanism and helps in impedance matching of the sound.
While preferentially feeding the oval window with sound waves, the tympanic membrane also gives protection to the round window. It shields the round window from the direct impact of the sound waves and allows it to function as a release point necessary for a fluid displacement of the inner ear.
Bone Conduction of Sounds
Besides air conduction, the sounds transmit through bone, which may be due to vibration of the skull by the subject’s sound waves, the free-field sound energy, or by application of the vibrating body directly to the head.
Stimulation of the sense organs by the bone-conducted sounds occurs through the compressional mechanism of the skull or by the inertia (lagging) of the ossicles and mandible as the head vibrates. The lagging behind of the mandible produces vibration of the cartilaginous meatus, then transmitted to the ear.
Functions of the Middle Ear Muscles
The primary function of the intratympanic muscles, the stapedius, and tensor tympani are to protect the inner ear from damage due to high-intensity sounds. Loud sounds reflexly stimulate the muscles, which cause stiffness of the ossicular chain, and thus less sound is passed into the inner ear. As these muscles have a latent period of contraction of 10 msec, these do not protect from sudden explosive sounds. Sound intensity of 70–90 dB above the hearing threshold is required to elicit the stapedial reflex.
Besides this reflex function, the intratympanic muscles help in supporting the ossicular chain.
Functions of Eustachian Tube
The eustachian tube helps in the aeration of the middle ear. Usually, an aerated central ear cavity is essential for the proper functioning of the tympanic membrane and ossicles. It provides a hypotympanic air bubble for the movement of the round window membrane.
The eustachian tube helps in the equalization of pressure in the middle ear. As the atmospheric pressure decreases, as during ascent in an airplane, the air in the central ear cavity gets absorbed, and a negative pressure develops inside the middle ear cavity. Equalizes frequent swallowing movements, which open the eustachian tubes. Failure to open the lines results in their closure (locking) and produces serous otitis media.
A similar situation occurs during the decompression phase in pressurized chambers.
Functions of the Mastoid Cellular System
The function of cellularity of the mastoid is not very clear. However, it may serve the following procedures.
- It may be an air reservoir for the middle
- It may be insulating chambers protecting
the labyrinth from temperature variations.
- It may provide resonance to sound.
Sensorineural Mechanism of Hearing
Once the sound waves are transmitted, the footplate of stapes causes movement of the cochlear fluids. It produces a ripple that causes displacement of the basilar membrane. The organ of Corti gets stimulated and results in the generation of cochlear microphonics.
The nerve impulses (action potentials) carry to the central connection.
ENT specialist Gurgaon Railway road knows all these functions, and that is why they are considered by almost every patient to visit when they suffer from any ENT problem.
DISTORTION IN THE EAR
There are several forms of sound distortion to which the ear, in common with other acoustic devices, is subjected. These are as follows:
Frequency distortion The “preferential” transmission of specific frequencies as compared to others occurs when the secondary system into which the sound transmits from the primary system cannot reproduce all frequencies with the same relative amplitude as does the primary system. In this sense, the close loss of high-frequency components in low pass filters is an example of frequency distortion.
Phase distortion Changes in the phase relationships of the constituent frequencies of a complex sound constitute phase distortion.
Amplitude distortion refers to the inability of a given system to reproduce the incident waveform properly. Both complex and straightforward wave motions can be affected by amplitude distortion.
To summarize, the best ear doctor in Gurgaon is not only qualified, but I have also studied deeply about the ear’s physiology, which helps them while practicing.