Physical & Behavioral Health in Audiology

Growth, Development and Aging

  • Hearing changes over the lifespan
  • inborn disorders, pregnancy and childbirth emergencies and environmental deficits can impact the development of speech and language
  • aging impacts hearing ability
    • cognitive ability declines w/ loss of hearing
  • it is important that you gain a "baseline" knowledge of these processes to better serve your patient

Post natal period

begins at birth and lasts until death
  • growth, development and aging are continuous processes that occur throughout the life cycle
    • often separated into stages
Five stages
  • infancy
  • childhood
  • adolescence
  • adulthood
  • older adulthood
    • through 2060, older adulthood is expected to have the largest percentage gain
Changes in body proportion
  • head becomes proportionally smaller
  • infant head is 1/4 of the total height of the body
  • adult head is about 1/8 of the total height of the body
  • facial bones show changes
    • infant face is 1/8 of surface
    • adult face is 1/2 of surface
  • the legs become proportionally longer
  • trunk proportionally shorter
  • thoracic and abdominal contours change roughly from round to elliptical

Infancy

Neonatal
  • first 4 weeks
  • many cardiovascular changes
  • respiratory changes and breathing ability
  • period of infancy begins at birth and lasts 18 months
Changes from 4 weeks to 18 months
  • birth weight doubles during first four months
  • birth weight triples by 1st year
  • increases in length by 50% by the 1st year
  • plump infant becomes leaner
    • bestows ability to stand
Nervous System Development
  • 2 months: follow a moving object
  • 3 months: lift head and raise chest
  • 4 months: sit when supported
  • 10 months: crawl
  • 12 months: stand alone
  • 18 months: run
  • Hearing and Understanding
Childhood
  • extends infancy to puberty; 12-14 years
Adolescence
  • 13-19 years
  • sexual hormones
Adulthood
  • growth plates fully close
  • degeneration begins
Older Adulthood
  • degenerative changes
  • organs undergo degeneration
Effects of Aging
  • Vision
    • eye lenses become harder
    • loss of transparency of lenses
  • Hearing
    • loss of hair cells
    • loss of elasticity of eardrum
    • fixing of ossicles
  • Cardio
    • degeneration of heart and blood vessels
    • fat deposits in blood vessels
    • hypertension and high blood pressure
  • Respiratory
    • calcification of ribs
    • wasting of respiratory muscles
    • thickening of respiratory membranes
  • Urinary
    • blood flow to kidneys decrease
    • bladder problems caused by muscle wasting
  • Skin
    • loses elasticity
    • pigmentation problems
    • thinning of hair
  • Skeletal System
    • calcification and change in shape of bones
    • bone spurs, bones become more porous
    • degeneration of joints
  • Mechanisms
    • Senescence: degenerative aging
    • cells die continually in a process called apoptosis
    • cells are not replaced causing degeneration of tissues
    • perhaps cells are not replaced because the surrounding cells have reached limit of production
    • perhaps differences in each individuals aging process result from differences in reproductive capacity of cells
    • slow acting aging viruses found in all living cells or aging genes which is preprogrammed
    • autoimmunity; oxygen free radicals play a major role
    • free radicals are highly reactive forms of oxygen that are normal byproducts of cellular respiration of mitochondrion
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Periods of development

  • length of pregnancy or gestation period is about 39 weeks
  • embryonic phase extends from 3rd week to end of week 8 of gestation
  • fetal phase extends from week 9 to week 39
  • all organ systems are formed and functioning by month 4 (16 weeks)
  • stem cells - unspecialized cells that reproduce to form specific lines of specialized cells
  • histogenesis and organogenesis
    • formation of new organs (organogenesis) and tissues (histogenesis)
    • gives rise to skin and muscles
    • differentiation, multiplication, growth and rearrangement
    • month 4 (16 weeks) to delivery, development is mainly growth
Birth/Parturition
  • week 39 uterus becomes irritable
  • fetus takes head-down position against the cervix
  • muscular contractions begin, labor initiated
  • amniotic sac (water) ruptures
  • cervix dilates
  • fetus moves through the vagina to exterior
Stages of Labor
  • onset of contractions until cervix dilation is complete
  • maximal cervical dilation until the baby exits the vagina
  • expulsion of the placenta
  • recovery is fourth stage of labor
  • Apgar scores assess general condition of infant
  • cesearean is delivery through abdomen wall
Apgar Score
  • rates respiration and crying
  • reflexes irritiability
  • pulse, heart rate
  • skin color of body and extremities
  • muscle tone
  • criterion
    • 0 - abnormal
    • 1 - below normal
    • 2 - normal
Hearing
  • check overall response to sudden sound
    • moro reflex
  • check for placement of ears
    • low set ears may indicate congenital anomaly
  • most infants receive hearing screening within the first week of life
  • HEARING LOSS IS THE MOST FREQUENT BIRTH DEFECT
    • undetected hearing loss has serious negative consequences
    • reading comprehension scores of hearing and deaf students
      • hearing loss have a much more difficult time statistically
        • math - 30th percentile
        • language - 25th percentile
        • social - 32nd percentile
Screening Techniques
  • AABR - automated auditory brainstem response
    • sounds presented through earphones
    • surface electrodes measure brainstem activity in response to sound
    • average test time: 20 minutes/baby
  • OAE - otoacoustic emissions
    • sounds are presented to the ear canal
    • small microphone measures the cochlear responses in the ear canal
    • average test time - 5-15 minutes per baby
Jaundice
  • yellow coloring of an infants skin
  • common and is caused by the natural breakdown of RBCs in the infant after birth
  • is never considered normal in the first 24 hours
  • most jaundice in newborns is physiologic
  • peaks between 48-72 hours
  • usually disappears within one week
  • usually benign
  • can become elevated to a point of concern for the baby
  • Bilirubin
    • bilirubin (orange/yellow pigment) is toxic to the brain
    • prevented from entering the brain by BBB under normal circumstances
    • BBB isn't well developed in newborns
    • un-conjugated bilirubin (lipid soluble) could cross to the newborn and cause encephalopathy (disease in which the function of the brain is disrupted by a toxin)
    • bilirubin is a component of the degradation of the RBC's
      • infants have extra RBC's due to fetal life
    • liver is immature and does not conjugate and get rid of the bilirubin fast enough
    • bilirubin toxicity affects the performance of the auditory nerve in several ways
      • more central nervous system is exposed to bilirubin, the more impact on hearing performance would occur
      • not possible to accurately determine exposure to bilirubin
      • it's consequence on hearing is highly variable and can range from slight hearing loss to complete deafness
      • studies have shown that hearing impairment due to kernicterus is more common in premature infants who develop high bilirubin levels
      • no direct connection between peak serum bilirubin levels and hearing thresholds
      • greater than 25 mg/dL there is a strong effect of decreased wave II and V amplitude
    • Phototherapy
      • fluorescent light/sunlight helps
      • blood exchange transfusion
Multiple births
  • identical twins result from splitting of the same zygote
    • genetically identical
  • fraternal twins result from fertilizing separate ova
Ectopic pregnancy
  • implantation outside of the uterus
Placenta Previa
  • separation of placenta from uterine wall, near cervix opening
Abruptio Placentai
  • normal placement, separated from uterine wall
Disorders of Pregnancy
  • Preeclampsia
    • high blood pressure
    • protein in the urine
  • Fetal Death
    • spontaneous abortion - loss before 20 weeks
    • stillbirth - loss after 20 weeks
  • Birth Defects
    • maybe inherited (congenital)
    • acquired defects from agents that disrupt normal development
Post-partum disorders
  • Puerperal fever
    • bacterial infection that may progress to septicemia 
  • Lactation
    • infant nutrition, disrupted by anemia, malnutrition and other factors
  • Baby Blues
    • 70-80% of women will experience depressive symptoms that will disappear in a few weeks
  • Postpartum depression
    • 10% experience some degree of postpartum depression which can last a year
    • emotional symtoms include
      • increased crying
      • irritability
      • hopelessness
      • loneliness
      • sadness
      • uncontrollable mood swings
      • feeling overwhelmed
      • guilt
      • fear of hurting self or baby
    • behavioral symptoms include
      • lack of or too much interest in the baby
      • poor self-care
      • loss of interest in otherwise normally stimulating activities
      • social withdrawal and isolation
      • poor concentration, confusion
    • physical symptoms
      • exhaustion, fatigue
      • sluggishness
      • sleeping problems (not related to screaming baby)
      • appetite changes
      • headaches
      • chest pain
      • heart palpatations
      • hyperventilation
    • risk factors
      • mental illness or substance abuse
      • marital or financial stress
      • birth complications
      • lack of self-confidence as a parent
      • problems with baby's health
      • major life changes around delivery
      • lack of support or help with baby
      • the mother being of young age
      • severe premenstrual syndrome
    • causes
      • exact cause unknown
      • levels of estrogen, progesterone, cortisol and thyroid hormones drop sharply at birth
  • Postpartum psychosis
    • can lead to child abuse, suicide and infanticide
    • symptoms include
      • delusions
      • hallucinations
      • sleep disturbances
      • obsessive thoughts about the baby
      • rapid mood swings
      • extreme anxiety, agitation
      • suicidal and homicidal thoughts​

The Influence of Hearing Aids on the Speech and Language Development of Children With Hearing Loss 

  • Importance
  • Hearing loss in children can be deleterious to their speech and language development. The standard of practice has been early provision of hearing aids (HA) to moderate these effects; however, there have been few empirical studies evaluating the effectiveness of this practice on speech and language development among children with mild to severe HL.
  • Objective
  • To investigate the contributions of aided hearing and duration of HA use to speech and language outcomes in children with mild to severe HL
  • Design, setting and participants
  • An observational cross sectional design was used to examine the association of aided hearing levels and length of HA use with levels of speech and language outcomes. One hundred eighty 3 and 5 year old children with HL were recruited through records of Universal Newborn Hearing Screening and referrals from clinical service providers in the general community in 6 US states.
  • Interventions
  • All but 4 children had been fitted with HAs and measures of aided hearing and the duration of HA use were obtained.
  • Main outcomes and measures
  • standardized measures of speech and language ability were obtained
  • Results
  • Measures of the gain in hearing ability for speech provided by the HA were significantly correlated with levels of speech and language. These correlations were indicative of modest levels of association between aided hearing and speech language outcomes. These benefits were found for children with mild and moderate to severe HL. In addition, the amount of benefit were found for children with mild and moderate to severe HL. In addition, the amount of benefit from aided hearing interacted with the duration of HA experience. Longer duration of HA experience was most beneficial for the children who had the best aided hearing.
  • Conclusions and Relevance
  • The degree of improved hearing provided by HAs was associated with better speech and language development in children. In addition, the duration of HA experience interacted with the aided hearing to influence outcomes. These results provide support for the provision of well-fitted  HAs to children with HL. In particular, the findings support early HA fitting and HA provision to children with mild HL.