Hearing impairment

  • Hearing impairment
    • This is defined as disability that may range in severity from slight to profound hearing loss.
    • Etiology
      • Anatomic malformation
        • Malformations of the head or neck
      • Family history
      • Low birth weight
      • Ototoxic drugs, O2 administration
      • Chronic ear infections
      • Perinatal asphyxia
      • Perinatal infections
      • Cerebral palsy
    • Pathology
      • Conductive hearing loss: Middle ear
      • Sensorineural hearing loss: Damage to inner ear or auditory nerve
        • The most common causes are congenital defects of inner ear structures or consequences of acquired conditions, such as kernicterus, infection, administration of ototoxic drugs, or exposure to excessive noise
        • This results in distortion of sound and problems in discrimination.
        • Although the child hears some of everything going on around him or her, the sounds are distorted, severely affecting discrimination and comprehension
      • Mixed conductive-sensorineural loss: Interference with transmission of sound
        • It frequently results from recurrent otitis media and its complications
      • Central auditory interception
        • Organic
          • The defect involves the reception of auditory stimuli along the central pathways and the expression of the message into meaningful communication.
            • Aphasia, the inability to express ideas in any form, either written or verbal; agnosia, the inability to interpret sound correctly 
            • Dysacusis, difficulty in processing details or discriminating among sounds.
        • Functional
          • No organic lesion exists to explain a central auditory loss. 
            • Hysteria (an unconscious withdrawal from hearing to block remembrance of a traumatic event)
            • Infantile autism
            • Childhood schizophrenia.
    • Therapeutic management
      • Conductive hearing loss
        • Many conductive hearing defects respond to medical or surgical treatment, such as antibiotic therapy for acute otitis media or insertion of tympanostomy tubes for chronic otitis media.
        • The nurse should be familiar with the types, basic care, and handling of hearing aids, especially when the child is hospitalized
          • Types of aids include those worn in or behind the ear, models incorporated into an eyeglass frame, and types worn on the body with a wire connection to the ear
          • One of the most common problems with hearing aid is acoustic feedback
            • Annoying whistling sound usually caused by improper fit of the ear mold.
        • As a nurse
          • Stress to parents the importance of storing batteries for hearing aids in a safe location out of reach of children and teaching children not to remove the battery from the hearing aid (or supervising young children when they do so). 
          • Battery ingestion requires immediate emergency management.
      • Sensorineural hearing loss
        • Treatment for sensorineural hearing loss is much less satisfactory.
          • This is because the defect is not one of intensity of sound, hearing aids are of less value in this type of defect.
        • The use of cochlear implants (a surgically implanted prosthetic device) provides a sensation of hearing for individuals who have severe or profound hearing loss
    • Clinical manifestation
      • Infants
        • Lack of startle or blink reflex to a loud sound
        • Failure to be awakened by loud environmental noises
        • Failure to localize a source of sound by 6 months of age
        • Absence of babble or voice inflections by 7 months of age
        • General indifference to sound
        • Lack of response to the spoken word; failure to follow verbal directions
        • Response to loud noises as opposed to the voice
      • Children
        • Use of gestures rather than verbalization to express desires, especially after 15 months of age
        • Failure to develop intelligible speech by 24 months of age
        • Monotone and unintelligible speech; lessened laughter
        • Vocal play, head banging, or foot stamping for vibratory sensation
        • Yelling or screeching to express pleasure, needs, or annoyance
        • Asking to have statements repeated or answering them incorrectly
        • Greater response to facial expression and gestures than to verbal explanation
        • Avoidance of social interaction; prefer to play alone
        • Inquiring, sometimes confused facial expression
        • Suspicious alertness alternating with cooperation
        • Frequent stubbornness because of lack of comprehension
        • Irritability at not making themselves understood
        • Shy, timid, and withdrawn behavior
        • Frequent appearance of being “in a world of their own” or markedly inattentive
    • When parents express concern about their child’s hearing and speech development, refer the child for a hearing evaluation. 
      • Absence of well-formed syllables (da, na, yaya) by 11 months of age should result in immediate referral.
    • Care management
      • Lipreading
        • Exaggerating pronunciation or speaking in an altered rhythm further lessens comprehension.
        • The child learns to supplement the spoken word with sensitivity to visual cues, primarily body language and facial expression (e.g., tightening the lips, muscle tension, eye contact).
          • Facilitating lipreading
            • Attract child’s attention before speaking; use light touch to signal speaker’s presence.
            • Stand close to child.
            • Face child directly or move to a 45-degree angle.
            • Stand still; do not walk back and forth or turn away to point or look elsewhere.
            • Establish eye contact and show interest.
            • Speak at eye level and with good lighting on speaker’s face.
            • Be certain nothing interferes with speech patterns, such as chewing food or gum.
            • Speak clearly and at a slow and even rate.
            • Use facial expression to assist in conveying messages.
            • Keep sentences short.
            • Rephrase message if child does not understand the words.
      • Cued speech
        • Method of communication is an adjunct to straight lipreading
        • It uses hand signals to help the hearing-impaired child to distinguish between words that look alike when formed by the lips (e.g., mat, bat). 
        • It is most employed by hearing impaired children who are using speech rather than those who are nonverbal.
      • Sign language
        • Encourage family members to learn signing, because using or watching hands requires much less concentration than lipreading or talking. 
        • A symbol method enables some hearing-impaired children to learn more and to learn faster.
      • Speech language therapy
        • The most formidable task in the education of a child who is profoundly hearing impaired is learning to speak. 
        • Speech is learned through a multisensory approach using visual, tactile, kinesthetic, and auditory stimulation. 
        • Encourage parents to participate fully in the learning process.
      • Additional aids
        • Flashing lights can be attached to a telephone or doorbell to signal its ringing. 
        • Trained hearing ear dogs can provide great assistance, because they alert the person to sounds, such as someone approaching, a moving car, a signal to wake up, or a child’s cry. 
        • Special teletypewriters or telecommunications devices for the deaf (TDD or TTY) help hearing-impaired people to communicate with each other over the telephone 
          • The typed message is conveyed via the telephone lines and displayed on a small screen.
      • Socialization
        • Classmates become a potential source of close friendships because they communicate more easily among themselves. 
        • Encourage parents to promote these relationships whenever possible.
        • In a group setting, it is helpful for the other members to sit in a semicircle in front of the hearing-impaired child. 
          • This is due to one of the difficulties in following a group discussion is that the hearing-impaired child is unaware of who will speak next, someone should point out each speaker. 
          • Speakers can also be given numbers, or their names can be written down as each person talks. 
          • If one person writes down the main topic of the discussion, the child can follow lipreading more closely. 
        • Such practices can increase the child’s ability to participate in sports, organizations such as Scouts, and group projects.
      • Support child and family
        • Parents need extensive support to adjust to the shock of learning about their child’s disability and an opportunity to realize the extent of the hearing loss. 
        • If the hearing loss occurs during childhood, the child also requires sensitive, supportive care during the long and often difficult adjustment to this sensory loss. 
        • Early rehabilitation is one of the best strategies for fostering adjustment. 
        • Progress in learning communication, however, may not always coincide with emotional adjustment. 
        • Depression or anger is common, and such feelings are a normal part of the grieving process.