Hearing Loss in Newborn Babies

Loss of Hearing in Newborns Due To ANSD

Hearing loss is a prevalent issue in newborn babies. This problem is due to Auditory Neuropathy Spectrum Disorder (ANSD), which is a complication that arises during the  transportation of sound from the inner ear to the brain. 

It is not known what the causes of ANSD are, but prematurely born infants or those who have a family history of this disorder have a higher risk of contracting it. Symptoms can begin at any age. Generally, children who have ANSD are born with it and have it diagnosed within the first few months after they are born.

As more research has developed ANSD has been detected more often. These diagnoses make up 10% to 15% of hearing loss cases.   

Luckily, children who have ANSD can develop solid communication and language skills with the help of assistive listening devices, therapy, and visual communication techniques. It is important to have the right diagnosis, along with early intervention. 
    
How Does Hearing Work?

To better understand ANSD, it’s helpful to know how your ears hear noise. Hearing starts out with sound waves that journey through the air and come in contact with the outer ear (the pinna), or the part of the ear that is visible. These sound waves are carried through the ear canal and into the middle section of the ear - this includes the eardrum (a fine layer of tissue) along with three small bones known as the ossicles. The eardrum reverberates when it comes in contact with sound. These vibrations become amplified by the ossicles and transport them to the inner ear.  

The inner ear is composed of the cochlea (a snail-shaped chamber), which is filled with fluid and interlined with four rows of microscopic hair cells. The outer hair cells contract back and forth to amplify sound when vibrations move through the fluid. When the vibrations reach the right size, the inner hair cells convert them into electrical nerve impulses in the auditory nerve, which links the ear and the brain to each other. When the nerve impulses come in contact with the brain, they are understood as sound.   

What is the effect of ANSD on Hearing?

Sound penetrates the ear in a normal manner for someone with ANSD, but due to damage in the inner row of hair cells or the synapses located halfway through the inner hair cells and the auditory nerve, or auditory nerve damage, sound will not accurately be carried from the inner ear to the brain.

The outcome of this causes sound waves that travel to the brain to become disorganized in a way that the brain is unable to comprehend. When it is disorganized, in some situations it never reaches the brain. In some instances, ANSD is caused by a complication with the auditory nerve.

There has only been a better understanding and diagnosis about ANSD in recent years. There is still more information that needs to be studied about it. Not every hearing screening for newborns can recognize ANSD, and as a result, there are many children and adults who have it but went undiagnosed. 

There are mild to severe symptoms of ANSD. Some children who suffer from ANSD have the ability to hear sounds, but have difficulty figuring out what the sounds are. Other people hear noises that all sound the same, similar to static or white noise. For example, someone’s voice may sound just like running water, a barking dog may sound just like a car horn, or a chirping bird may sound like a clanging pans. 

For some, ANSD gets better after some time. For others, it might stay the same or worsen.

Causes of ANSD  

The causes of ANSD are unknown. There are some risks that may influence whether a child is susceptible to the disease, which include:
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• Ailments in infants, such as jaundice 
• Anoxia and hypoxia
• Family history of ANSD
• Head trauma
• Low birth weight
• Premature birth

Symptoms

Even if a child passes a newborn hearing screening, the symptoms of hearing problems might not be noticed for years. 

Have you noticed any of the following symptoms:
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• Your baby does not get startled at the sound of loud or abrupt noises, or does not turn toward sound.
• Your baby is not babbling, cooing, or laughing by 8 months.
• Your baby does not attempt to imitate sounds and actions by the time they reach 12 months, or is unresponsive to easy instructions.

Treatment

There is no cure for ANSD, but an assistive listening device (ALD) can be helpful for children who have ANSD make sense of the sounds around them and develop skills for language. Getting treatment for ANSD depends on the severity of the disease and how old a child is when they are diagnosed. 

To make any of these devices effective it is important to have continuous therapy with a speech-language pathologist who specializes in aiding children with hearing loss,  speech development and hearing abilities. 
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If your child is in need of hearing aids or an ALD, contact us at Pure Sound Hearing.

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