Hearing screening is a method of checking hearing in the first days of a child’s life. The frequency of congenital hearing impairment (as the most common sensory deficit, unchanged for decades) is that in every thousand newborns, one or two cases are diagnosed with hearing loss.
It is important to detect hearing impairment as early as possible, which is why hearing screening has been introduced as a routine examination. If a disability is detected early, it is easier to respond and prevent serious consequences. Prompt intervention is crucial because hearing loss can affect the development of the central nervous system as well as speech development.
Neonatal hearing screening is performed in the first days after birth, and no later than the end of the first month. It is conducted in maternity hospitals using a device that measures otoacoustic emissions. Otoacoustic emissions are sounds emitted by healthy ear cells, so if otoacoustic emission is absent, it indicates the presence of damage. The device automatically shows the result – if everything is fine with the hearing, the device will show “Pass,” and if the baby does not pass the test, it will show “Fail.” Not every negative result indicates hearing impairment; in screening there is a significant difference between children who were born prematurely or were in intensive care compared to full-term babies. Also, results may be negative if there is a foreign object in the ear, fluid in the external ear canal, negative pressure, or excessive noise in the room. During the exam, the baby must be calm, and the room must be quiet. Screening is not done on the first day of life because otoacoustic emissions are not fully mature, which may produce false results. In this way, the presence of hearing impairment can be detected as early as possible, and if the child does not pass the test, they are referred for audiological examinations to determine the degree of hearing loss.
Various tests can be used in hearing evaluation, such as:
- Behavioral audiometry – assessing the reaction to sound
- Pure tone threshold audiometry
- Speech audiometry
- Tympanometry – examining the function of the middle ear
- Otoacoustic emissions
- Auditory evoked potentials (ABR, BERA) – represent changes in brain electrical activity during exposure to sound.
None of the listed tests are absolutely accurate. That’s why various combinations of tests are used in hearing evaluation to obtain the most accurate result, i.e., to make the best assessment of the degree of hearing loss.