Hearing in Infants Ages Birth to 12 Months: Child Growth and Development Tamesha Robinson Collin College

Child Growth and Development TECA 1354 Professor Susy A Mathews Associate Faculty Office SCC B-103 or Child Development Lab School Spring Creek Campus

Development of Hearing in the Womb Infants sense of hearing under goes most of its development in the womb (Baby center) states that a baby’s inner ear fully develops by the 20th week of pregnancy. The ability to hear is fully developed at birth. While in the womb, babies can hear your heart beat, your stomach grumbling and the blood moving through the umbilical cord. Babies are even startled by loud noises. The results suggest newborns will gravitate toward and pay more attention to what may be “their mothers melodic sounds than those of other women, and will pay more attention to other similar sounds like female voices in general, than they will to even less similar sounds, like male voices.
The findings add to evidence suggesting that prenatal hearing can help infants perceive the sounds of speech. It was long know that newborns can discriminate or perceive most of the acoustic properties of speech. The theoretical view is that these capacities are mostly independent of previous auditory experience and that newborns have a bias or skill for perceiving speech. Scientist believe the newborns capacity to perceive speech is physiologically “built in’ during development of the auditory system. A study in Proceeding of the National Academy of Science reinforce what many people have believed babies hear what their moms say and their brains recognize these words after birth. What unborn babies hear can shape their brain. Infants in the womb can hear with little or no distortion not only the voice of their mother but conversations near them. 5 weeks before birth, the cochlea the spiral-shaped part of the inner ear responsible for hearing is usually mature. To see if babies can actually remember sounds from back that far, developmental psychologist Carolyn Granier-Deferre at Paris Descartes University in France and her colleagues played melodies to infants inside the womb and then tested them after they were born. Fifty women were asked to play a brief recording of a descending piano melody (one that gets lower in pitch twice daily in the 35th, 36th, and 37th week. The melody was nine notes long and lasted 3.6 seconds. When the women’s 50th infants were 1 month old the descending melody and an ascending nine-note piano melody were played to the babies while they slept in the researcher’s dimly lighted laboratory. The scientists found on average the heart rates of the sleeping babies briefly slowed by 12 beats a minute with the familiar descending melody. Only 5 to six beats with the unfamiliar melody this deceleration means the 1 month old infants paid more attention to the familiar melody than they did to the unfamiliar melody, even though they had not heard it for six weeks. When it comes to devices put directly on a mother’s skin to play music this kind of stimulation can be harmful to the fetal ear if it is too loud or left on too long or applied too early during the inner ear development. Scientist adds if a mother wants to sing to her baby why not? A mothers singing is a wonderful part of the natural sound of our environment.

Hearing in Infant: Ages Birth to 12 months Even though a new born baby can sleep through a lot of noise they are likely to be startled by loud sounds. Before 3 months of age responses to noise can be based on temperament. If he/she is calm and relaxed, loud noises may not bother them as much as they would if their fussy. By 4 to 6 months old babies can turn their head when they here a Parents voice and may look for the source of a sound. At 6 months of age, baby may be able to imitate inflections that they hear in your voice. As a baby approaches 10 months of age they respond to their name and other familiar sounds or words such as the telephone. Around 12 months they can point to familiar objects in a book when asked. Babies use their ears to take in massive amounts of information about the world around them. Hearing also enables them to learn language and stimulates brain development. Babies can hear and listen even before they are born. At birth, their hearing is similar to an adults. Babies learn by listening to sounds and voices. They learn to connect the sounds they hear with the people, animals, objects, and actions that made them. This is how they are able to make sense of the world around them. As babies grow and develop, they’ll use their hearing to communicate and interact with others. The ability to hear is an important sense to development normal speech and language skills. Hearing can be encouraged by having different ways of holding and talking to your baby. Some babies need energetic conversation, some need gentle tones. Another way to encourage hearing is by talking and reading often. This will allow babies sense of hearing and cognitive abilities to develop together. It’s important to know what to expect as your baby develops because hearing problems can delay the development of voice, speech, and language skills. To recognize developmental delays you can keep track of your babies development by age appropriate checklist that can be addressed by a doctor if not accomplished at their age level. Hearing checklist for ages birth to 6 months: Child should react to loud sounds, Calm down or smile when spoken to, Recognize your voice and calm down if crying, When feeding starts or stop sucking in response to sound, Coos and makes pleasure sounds, Has a special way for crying for different things. 4 to 6 months follow sound with his or her eyes, Respond to changes in the tone of your voice, Notice toys that make sound, Pay attention to music, Babbles in a speak-like way and uses many different sounds, Including sounds that begin with p,d, and m, Laughs, Makes gurgling sounds when alone or playing with you.

Hearing Impairments in Infants: Birth to 12 months They are many was to encourage hearing and to protect your babies hearing but there are some unfortunate cases when a babies hearing is impaired. Hearing impairment is the decreased ability to hear and discriminate among sounds. It is one of the most common birth defects. Each year in the United States about 12,000 babies (3 in 1,000) are born with some degree of hearing impairment. The centers for Disease Control and Prevention (CDC) recommended that all babies be screened for hearing impairments before 1 month of age, preferably before they leave the hospital after birth. This because language and communication develop rapidly during the first 2 to 3 years of life, and detected hearing impairments can lead to delays in developing these skills. Without newborn screening children with hearing impairment often are not diagnosed until 2 to 3 years of age. Hearing impairments can be genetic (inherited) or non-genetic. Non-genetic causes include illness or injury before, during, or after birth. In some cases it is not known what the cause is. About 90 percent of babies with congenital hearing impairment are born to parents with normal hearing (1, 2). Genetic factors are believed to cause 50 percent of cases of hearing impairment in infants and young children (1) Scientist believe that mutation (changes) in as many as 400 genes may contribute to hearing impairment (1,3).
Genetic Causes of Hearing Impairment:
Syndromatic: Syndromatic means that the hearing impairment happens with a specific group of birth defects.
Non-Syndromatic: Non-syndromatic means that hearing impairment is the only birth defect a baby has. About 50 percent of cases of non-syndromatic gentic hearing impairment are caused by a mutation in a gene called connexin 26(3). About 25 percent of cases of hearing impairment are caused by non-genetic factors (1) these include premature birth (before 37 weeks of and illness during pregnancy.
*Rubella (German Measles’s)
*Cytomes alovirus infections
*Toxoplasmosis
*Herpes infection
*Syphilis
Non-genetic causes of hearing impairment after birth include
*Head injures
*Childhood infections (such as meningitis) measles or chicken box
*Certain medications (Such as the antibiotic streptomycin and related drugs)
*Ear infections hearing impairment however frequent and poorly treated ear infections can cause permanent hearing impairment. There are many things that we can expect and look forward to with the development of a child’s hearing at this developmental stage birth to 12 months children must be properly cared for to see changes that will positively affect their hearing. This hearing stage should be treated in the same manner as other important as physical or cognitive development. Parents must become aware of the support that hearing can give to speech and language in young children. Taking certain suggestions and precautions can determine the growth and success of your child hearing.

References

Meghar Holohan NBC News August 26, 2013 at 4:30pm National Institute on Deafness and other Communication Disorders (NIDCD) WIH Publication N O 10-4040 Updated September 2010 Live Science Contributor March 4, 2011 Growing Miracles “Alberta Health Services 2010 Baby Hearing, Kids Health, How will I know if my child has trouble hearing, Developmental Milestones Hearing: February 23 in the Journal PLOS one.

Tamesha Robinson Collin College