Deafness: Sensory Disabilities

Deafness

Individuals with extreme hearing loss (90 dB or greater) rely on visual communication, as they cannot process linguistic information through hearing, even with amplification.

Hard of Hearing (Partial Hearing)

Individuals with residual hearing can still process speech with the help of hearing aids or other auditory tools.

Factors in Defining Hearing Loss:

1. Age of Onset:

2. Anatomical Site of Hearing Loss:

Age of Onset, Factors in Defining Hearing Loss:

Age of Onset

• Prelingual loss - hearing impairments occurring prior to the age of 2, or the time of speech development.

• Postlingual loss - hearing impairments occurring at any age following speech development.

Prelingual loss

hearing impairments occurring prior to the age of 2, or the time of speech development.

Postlingual loss

hearing impairments occurring at any age following speech development.

Anatomical Site of Hearing Loss, Factors in Defining Hearing Loss

A.

• Conductive Hearing Loss – Caused by poor conduction of sound along the passages leading to the sense organ.

• Sensorineural Hearing Loss – resulting from an abnormal sense organ (inner ear) and a damaged auditory nerve

• Mixed Hearing Loss – A combination of conductive and sensorineural issues.

B. Central Auditory Disorder – Occurs when there is a dysfunction in the cerebral cortex

Conductive Hearing Loss

Caused by poor conduction of sound along the passages leading to the sense organ.

Sensorineural Hearing Loss

resulting from an abnormal sense organ (inner ear) and a damaged auditory nerve.

Mixed Hearing Loss

A combination of conductive and sensorineural issues.

Central Auditory Disorder

Occurs when there is a dysfunction in the cerebral cortex.

0 - 13 db

Normal hearing

16-25 db

Slight hearing loss

Minimal difficulty with soft speech

26-40 db

Mild hearing loss

Difficulty with soft speech

41-55 db

Moderate hearing loss

Frequent difficulty with normal speech

56-70 db

Moderate to severe hearing loss

Occasional difficulty with loud speech

71-90 db

Severe hearing loss

Frequent difficulty with loud speech

>91 db

Profound hearing loss

Near total or total loss of hearing

Mild and Moderate Deaf on Language Skills

Effects:

Minimal

Approach:

Effective communication skills are possible because the voiced sounds of conversational speech remain audible.

Congenitally deaf on Language Skills

Effects:

• These people are unable to receive information through speech unless they have learned to lip-read.

• Exhibit significant problems in articulation, voice quality, and tone discrimination.

Approach:

• Provide early and specialized training in English language production and comprehension.

• Teach sign language long before they learn to speak.

Prevalence of Deafness in USA

• Estimation of 30 million people with hearing loss in the United States

  • 11 million people have significant irreversible hearing loss and one million are deaf

  • Only 5 percent of people with hearing loss are under the age of 17; nearly 43 percent are over the age of 65.

Prevalence of Deafness in the Philippines

• Approximately 1,784,690 deaf or hard-of-hearing Filipinos (Philippine Statistics Authority, 2020.)

• Men are more likely than women to have a hearing loss.

Causes and Risk Factors of Deafness

1. Heredity - Genetic defects that cause hearing loss are usually rare, they are not included in routine prenatal genetic screenings.

   Infections:

   • Otosclerosis

2. Prenatal Disease - Several conditions, although not inherited, can result in sensorineural loss.

   a. Infections:

   • Rubella

   • Congenital Cytomegalovirus

   • Congenital Toxoplasmosis Infection

   b. Other causes:

   • Rh-factor incompatibility

   • Ototoxic drugs

   • Atresia

3. Postnatal Disease

   • Measles, Mumps, Influenza, Typhoid Fever, and Scarlet Fever - are all associated with hearing loss

   • Meningitis

   • Otitis media

4. Environmental Factors

   • Loud noise

   • Degenerative processes in the ear

Hereditary Factor, Otosclerosis

Abnormal bone remodeling in the middle ear. One of the most common diseases affecting the sense of hearing. It is generally believed to be hereditary and is manifested most often in early adulthood.

People with otosclerosis experience high-pitched throbbing or ringing sounds known as tinnitus. 

Surgery (stapedectomy) may be recommended when the stapes (stirrup) bone is involved.

Prenatal Disease Factor, Rubella

If a pregnant woman gets rubella, her baby may be born deaf. Most hearing losses caused by rubella are sensorineural, although a small percentage may be mixed. The rubella (MMR) vaccine has helped reduce cases.

Prenatal Disease Factor, Congenital Cytomegalovirus (CMV)

Viral infection that is spread through body fluids. Preventive measures are ensuring safe blood transfusions, practicing good hygiene, and avoiding contact with people who have the virus.

Prenatal Disease Factor, Congenital Toxoplasmosis Infection

Characterized by jaundice and anemia and approximately 13 percent of infants born with this disease are deaf.

Other Causes Factor, Rh-factor incompatibility

As antibodies are produced during subsequent pregnancies, multiple problems can result, including deafness. If anti-Rh gamma globulin (RhoGAM) is injected into the mother within the first 72 hours after the birth of the first child, she does not produce antibodies that harm future unborn infants.

Other Causes Factor, Ototoxic drugs

Some medications taken during pregnancy can damage a baby’s hearing.

Other Causes Factor, Atresia

The external auditory canal is either malformed or completely absent at birth. A congenital malformation may lead to a blockage of the ear canal through an accumulation of cerumen, which is a wax that hardens and blocks incoming sound waves from being transmitted to the middle ear.

Postnatal Disease Factors, Measles, Mumps, Influenza, Typhoid Fever, and Scarlet Fever

are all associated with hearing loss.

Postnatal Disease Factors, Meningitis

Postnatal Disease Factors, Otitis media

an inflammation of the middle ear. It often happens after a bad cold and affects 3 out of 4 children by age 3.

Environmental Factors, Loud noise

Is rapidly becoming a major cause of hearing problems (e.g., noise from jet engines and loud music, occupational noise).

Environmental Factors, Degenerative processes in the ear

may come with aging, cerebral hemorrhages, allergies, and intercranial tumors.

Assessment of Hearing Loss

Therapeutic procedures:

• Monitoring aural hygiene (e.g., keeping the external ear free from wax)

• Blowing out the ear (e.g., a process to remove mucus blocking the eustachian tube)

• Administering antibiotics to treat infections.

Surgical techniques:

• Fenestration

• Stapedectomy

• Myringoplasty

• Cochlear Implant

Fenestration

the surgical creation of a new opening in the labyrinth of the ear to restore hearing.

Stapedectomy

a surgical process conducted under a microscope whereby a fixed stapes is replaced with a prosthetic device capable of vibrating, thus permitting the transmission of sound waves.

Myringoplasty

the surgical reconstruction of a perforated tympanic membrane (eardrum).

Cochlear Implant

An electronic device is surgically placed under the skin behind the ear. The implant overcomes “nerve deafness” (sounds blocked from reaching the auditory nerve) by getting around damage to the tiny hair cells in the inner ear and directly stimulating the auditory nerve.

Four parts of the electronic device: 

( 1 ) Microphone (picks up sound) 

( 2 ) Speech processor (organizes sound) 

( 3 ) Transmitter & receiver (converts sound into electrical signals) 

( 4 ) Electrodes (send signals to the brain)

Otologist

a medical specialist who is most concerned with the hearing organ and its diseases. They conduct an extensive physical examination of the ear to identify syndromes that are associated with conductive or sensorineural loss. This information, in conjunction with family history, provides data used to recommend appropriate medical treatment that may involve medical therapy or surgical intervention.

Audiologist

a specialist in the assessment of a person’s hearing ability. Emphasizes the functional impact of losing one’s hearing. Audiologists first screen individuals for a hearing loss and then determine both the nature and the severity of the condition. Social, educational, and vocational implications of the hearing loss are then discussed and explored.

Three Types of Hearing Aids

1. The body-worn aids - worn on the body, rather than in or on the ear. 

2. The behind-the-ear aid (ear-level aid) - a common electroacoustic device for children with a hearing loss. All components of the behind-the-ear aid are fitted in one case behind the outer ear. fitted monaurally (on one ear) or binaurally (on both ears).

3. The in-the-ear aid - fits within the ear canal. All major components (microphone, amplifier, transducer, and battery) are housed in a single case that has been custom-made for an individual user.

The body-worn aids

worn on the body, rather than in or on the ear. 

The behind-the-ear aid (ear-level aid)

a common electroacoustic device for children with a hearing loss. All components of the behind-the-ear aid are fitted in one case behind the outer ear. fitted monaurally (on one ear) or binaurally (on both ears).

The in-the-ear aid

fits within the ear canal. All major components (microphone, amplifier, transducer, and battery) are housed in a single case that has been custom-made for an individual user.

2018: Filipino Sign Language Law

(Republic Act No. 11106)