By Dr Ananya Mandal, MD
Hearing loss may appear during childhood or later in life or may be present since birth. There are numerous causes of hearing loss and depending on the cause the symptoms vary between individuals.
Hearing loss can gradually develop over time especially if it is age related hearing loss or develop after a short illness if it is related to an acute infection of the middle ear.
Many patients may present with hearing loss along with other symptoms such as dizziness, ringing of the ears or tinnitus and feeling of pressure within the ear(s). 1-5
Symptoms of Congenital hearing impairment
Hearing impairment may be present in some conditions since birth. The symptoms of this condition include:
- the baby not being startled with a loud noise
- not turning his or her head to the source of a sound while under four months old
- not say any word even by the age of one
- sees the mother but does not respond to her calling him or her
- seems to hear some sounds but not all sounds
In general, children with delay in learning to talk, unclear speech, talking loudly or asked the speaker to repeat themselves and turning up the volume of the TV so that it is very loud indicates that there may be hearing impairment.
Symptoms of hearing loss
Common complaints include:
- difficulty in hearing and understanding conversations
- difficulty in following conversations over the telephone
- listening to music or television at a volumes higher than other persons
- missing door bells or phone rings
- difficulty placing the direction of the oncoming sound
Patients often ask the speaker to repeat and have more difficulty in understanding women and children. They may also have a history of working in a noisy environment.
Symptoms of mild hearing impairment
This means that the patient can hear the quietest sounds between 25 to 39dB. This type of hearing loss means difficulty in understanding whispered speech.
Symptoms of moderate hearing impairment
These persons can hear the quietest sound between 40 to 69dB. A normal conversation becomes difficult for these persons to follow.
Symptoms of severe hearing impairment
The quietest sound that these patients can hear is between 70 to 89dB. These patients cannot hear shouted words and may need sign language for communication.
Symptoms of profound hearing impairment
These patients cannot hear very loud sounds that normally hurt the ears of normal hearing persons.
Other symptoms of hearing loss
Other symptoms include:
- discharge of clear fluid or pus from the ears
- pain in the affected ear
- tinnitus or ringing of the ear
- feeling of fullness of the affected ear
Diagnosis of hearing loss
Diagnosis of hearing loss involves ear examination, hearing tests and so forth.
The external ear canal is examined using an otoscope or an auriscope. This helps in detection of a blockage in the ear canal with ear wax or with a foreign object (e.g. a bead), ear canal infection, bulging eardrum indicating an acute middle ear infection, perforation of the ear drum and collection within the ear.
These are performed using a tuning fork test. A tuning fork is a Y-shaped, metallic object. It is tapped and this releases sound waves at a fixed pitch. The tuning fork is then held close to either ear to detect hearing impairment in the ear.
The physician may also whisper near the ear to detect loss of hearing in the ear. This tests for air conduction of the sound.
Tuning fork tests
A hearing test is followed by further tests called tuning fork tests. Once the tapped tuning fork begins to vibrate, it is held against the bone behind the ear called the mastoid bone.
The sound waves move to the ear and the person hears the sound in the normal ear. This tests for the bone conduction of the sound.
This is also called Pure Tone Audiometry. Both air and bone conduction can be tested using audiometry. For air conduction, sounds are transmitted to the ear using earphones and the patient is asked to indicate when he or she hears the sound.
Bone conduction is tested to see how well the sound is transmitted through the bone rather than the air. These check for the nerves that transmit sound to the brain as well.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)