WHAT IS HEARING?
Before defining hearing loss, it is useful to briefly mention how the auditory system functions in healthy individuals.
First of all, after the sound waves in our environment are collected by the auricle, they are transmitted to the cochlea through the external auditory canal and middle ear structures. After the necessary transformations in the cochlea, the signals are transmitted to the auditory nerve and from there to the brainstem and cortical centers. After the synthesis and interpretation made here, hearing occurs.
Hearing loss refers to a decrease in hearing sensitivity and difficulty in perceiving sounds due to pathologies occurring at any stage of the hearing pathways mentioned above. Hearing loss impairs individuals' speaking and understanding skills, and prevents them from communicating with individuals around them and causes social problems.
Hearing loss may be congenital or acquired.
These ;
Transmission type
Sensorineural type
mixed type
It can be classified as central type.
Conductive Hearing Loss;
External ear
external ear canal
Eardrum
It is caused by a pathological cause consisting of middle ear structures.
Conduction loss prevents the amplification of sound through the outer and middle ear structures and its passage to the cochlea. Sensorineural hearing loss is caused by a disorder in the cochlea, auditory nerve or central auditory pathways and can occur due to many different pathologies.
Causes of Hearing Loss;
It is necessary to classify the causes of hearing loss according to which part of the auditory system the pathology occurs.
Causes related to the Outer Ear;
Foreign body in the external ear canal
Bushon (earwax)
Absence of auricle or congenital deformity
Congenitally closed external ear canal
outer ear canal infection
External ear canal tumors
Causes Related to Middle Ear;
Fluid accumulation in the middle ear space
Perforation of eardrum
cholesteatoma
middle ear infection
Hardening and calcification of the middle ear ossicles
Trauma (cranial fractures, ossicle injuries, membrane rupture)
middle ear tumors
Metabolic and systemic diseases
Genetically transmitted diseases
Causes Related to the Inner Ear and Auditory Nerve;
Ear and head injuries
inner ear infections
Infections (mumps, rubella, etc.)
Prolonged exposure to loud noise
Harmful (ototoxic) substances and drugs to the inner ear
Hearing loss due to aging
Meniere's disease (dizziness, buzzing)
Auditory nerve tumors
Systemic diseases (diabetes, thyroid, etc.)
Some diseases experienced by the mother during pregnancy
Some medications used during pregnancy
Spurs experienced during birth (premature birth, lack of oxygen after birth, etc.)
genetic factors
WHAT ARE THE TYPES OF HEARING TEST?
There are 4 different types of hearing tests: pure tone audiometry, speech audiometry, tympanometry and acoustic reflex tests.
Pure Tone Audiometry;
It is the most commonly performed hearing test. Pure tone audiometry determines the minimum sound intensity that both ears can hear at different frequencies. In a soundproof cabin, the patient listens to sounds through a special headset. With the help of the button, one can get an idea of ??whether the patient hears these sounds or how much he hears them. Pure sound Extra attention should be paid to some situations when performing audiometry.
These situations are:
If the patient has a complaint of tinnitus, this situation should be reported to the audiometrist and the audiometrist should be informed about this and the sound should be sent in a special tone for patients with tinnitus complaints called warble.
Patients should press the button not only at the loudest sound they hear, but also at the lowest sound.
If the bone conduction sound conductor is burned, one should remain as still as possible.
Speech Audiometry;
Hearing and evaluating the human voice, which is the basic function of the ear, forms the basis of speech audiometry. As a stimulus and evaluating the state of the sound in the ear, providing information about the person's ear functions is the main task of speech audiometry. The thresholds determined for this test are the speech reception threshold, speech discrimination threshold, comfortable hearing. listening threshold and disturbing level.
Tympanometry;
By applying air pressure to the outer ear canal, which measures the pressure of the middle ear, the mobility of the middle ear and its membrane is measured. This test can be easily performed even on babies. The eardrum must not have a hole during the typanometry test.
Acoustic Reflex Tests;
It provides information about the hearing pathways down to the brainstem level. The information obtained by the acoustic reflex hearing test is interpreted together with other findings and gives an idea about the location of the condition causing hearing loss.
What are the Degrees of Hearing Loss?
normal hearing loss
Mild loss of function
moderate hearing loss
Severe hearing loss
severe hearing loss
