How to prepare for your baby's first hearing test

Author: Zhang Liya, Deputy Chief Physician, Women's and Children's Hospital Affiliated to Ningbo University

Reviewed by: Chen Zheng, Chief Physician, Children's Hospital Affiliated to Zhejiang University.

Hearing impairment is one of the most common congenital defects found in newborns. It adversely affects not only a child's language development but also has long-term detrimental impacts on cognitive and social abilities. Newborn hearing screening, a simple, rapid, and non-invasive method of examination, plays a vital role in the early detection of hearing issues and subsequent interventions. Even in families with no history of hearing problems over several generations, newborns should still undergo standardized hearing screening. This article systematically introduces the importance of newborn hearing screening, the methods involved, and relevant precautions.

The Importance of Newborn Hearing Screening

Hearing is crucial for infants to learn language and interact with their surroundings. If there are hearing issues, children may miss vital periods for language acquisition, leading to delays in language development that can hinder future learning and social skills. The primary objective of newborn hearing screening is to identify potential hearing problems as early as possible, allowing for timely interventions, such as the use of hearing aids or cochlear implants, which can maximize hearing restoration or improvement.

Certain genes associated with deafness, such as GJB2 (gap junction protein beta 2 gene) and SLC26A4 (solute carrier family 26 member 4 gene), have pathogenic mutations that are not uncommon among the hearing population in our country. This type of inheritance is primarily autosomal recessive, meaning that parents with normal hearing may still be carriers of the same pathogenic gene, potentially leading their children to hereditary hearing loss. Therefore, newborn hearing screening is not just a function assessment but also aids in the early detection of possible hereditary conditions, providing a crucial opportunity for subsequent interventions.

Common Methods for Neonatal Hearing Screening

Presently, the commonly used methods for neonatal hearing screening include objective electrophysiological tests, which mainly consist of the following two types:

1. Auditory Evoked Emissions Test

Specialized equipment is utilized to record sound responses in the external ear canal, employing weak sound signals generated under normal conditions within the ear canal. These signals bounce back to the eardrum, generating measurable electrical signals. In cases of hearing impairment, these signals may decrease or vanish. This method is appropriate for the preliminary assessment to determine whether newborns have hearing abnormalities.

2. Auditory Brainstem Response (ABR) Test

Electrodes are placed on the baby's head while a series of sounds at varying frequencies are played. A computer system analyzes the recorded electrical signals to identify any hearing issues. This test assesses hearing function by monitoring the response of specific brain areas to sound stimuli, making it suitable for a more thorough evaluation of newborns' hearing status.

Additionally, a hearing assessment questionnaire can assist in diagnosing hearing issues in newborns. By querying parents about their baby’s daily behaviors, such as responses to sounds or enjoyment of music, it aids in understanding the baby's hearing condition.

The Process of Newborn Hearing Screening and Parental Considerations

Newborn hearing screening typically occurs within 48 hours after birth, prior to discharge, and is divided into two stages: the initial screening and retesting. Newborns who do not pass the initial screening are required to undergo retesting by 42 days after birth. If they continue to fail the retest, they must be referred to a higher-level pediatric audiology diagnostic institution for a hearing diagnostic examination within three months of birth.

During the screening process, parents should be mindful of the following points:

1. Maintain a quiet environment. During screening, it is crucial to ensure a quiet setting to avoid any noise interference affecting the test results.

Parents should actively cooperate with the physician during the examination, ensuring that the baby is in a natural sleep or calm state to obtain accurate test results.

3. Rationally assess the screening results. A failed screening result does not necessarily indicate hearing impairment; it may be influenced by factors such as environmental noise during the test, improper handling, or lack of cooperation from the infant. Multiple reassessments and further diagnostics are essential for a conclusive determination.

Interventions and Follow-up After Screening Abnormalities

If the hearing screening results show abnormalities, a professional hearing assessment and intervention should be arranged as promptly as possible to ensure timely correction of any hearing issues. Interventions may include medications, the use of hearing aids, cochlear implants, and gene therapy, with specific plans customized based on the child's individual circumstances and physician recommendations.

Simultaneously, regular follow-up check-ups are necessary to monitor changes in hearing and adjust treatment strategies accordingly. As hearing may fluctuate with growth, parents should ensure their children undergo regular hearing assessments to safeguard their hearing health.

Conclusion

Newborn hearing screening is an integral aspect of child healthcare, vital for the early identification of hearing impairments, timely interventions, and the enhancement of children’s language and cognitive development. Even without a family history of hearing loss, parents should actively cooperate to complete the hearing screening. Through early detection, diagnosis, and intervention, we can significantly improve rehabilitation outcomes for children with hearing impairments, facilitating their integration into the auditory world.

References

Notice from the Ministry of Health regarding the publication of the "Technical Specifications for Neonatal Disease Screening (2010 Edition)". Journal of the Ministry of Health of the People’s Republic of China, 2011, (1): 12-22.