OAE screening is a first step in identifying children who need further audiological assessment. But what happens after screening? Following the recommended protocol, a child not passing the initial or subsequent OAE screening will typically be referred to a health care provider who will look for common middle ear problems. After any observable conditions are resolved, an OAE rescreen is conducted and if the child does not pass this rescreen, it is time to access the expertise of a pediatric audiologist to find out whether a permanent hearing loss is present. Each of the child's ears should be evaluated by the audiologist even if only one ear did not pass the screening.  

Having a basic understanding of what a pediatric audiologist will do during the evaluation process will help you to prepare and reassure parents. The evaluation process should include:

Child and family history. Parents will be asked about their perceptions of their child's ability to hear, respond, and communicate. They will also be asked about any family history of childhood hearing loss, conditions that occurred during pregnancy (including maternal illnesses, complications that occurred during labor or delivery, etc.), and whether the infant spent time in the neonatal intensive care unit (NICU) after birth.

Otoscopic inspection. Visual examination of the ear canal and tympanic membrane (ear drum).

Otoacoustic emissions (OAE) testing.  The process is similar to OAE screening. A small probe, covered with a soft tip, is placed in the child's ear canal. The equipment presents a series of soft sounds and analyzes the inner ear response to the sounds. In OAE testing, the audiologist will look at frequency(pitch)-specific responses. When a child is cooperative, this part of the evaluation takes only a minute or two.  

Tympanometry and acoustic reflex testing.  Although not specifically a test of hearing, these tests play an important role in evaluating the function of the auditory system. A small probe portion of a tympanometer is placed in the child's ear to seal the canal. The tympanometer then presents a sound and changes the air pressure in the ear canal while analyzing the response of the tympanic membrane (ear drum) and the small bones and muscles in the middle ear. When a child is cooperative, this part of the evaluation takes only a minute or two. A specialized tympanometer that can generate a high-frequency (1000Hz) probe tone should be used for children 0-6 months of age.  

Behavioral audiometry. This part of the assessment can take some time because the child has to learn how to respond to sounds.  Typically, one of two two types of earphones and then a bone vibrator are placed on the child.  (For very young children,
a loudspeaker in the test room may occasionally be used.) The audiologist will attempt to observe the lowest intensity (threshold) at which the child can detect sound at different frequencies (pitches).

• For infants 6-36 months of age, visual reinforcement audiometry (VRA) is often the preferred method. The infant/child is seated on a caregiver's lap in a soundproof booth and the child is trained to turn toward a toy (one that lights up and/or moves) when he/she hears a sound.


• For toddlers 24 months of age or older, an alternate method, called conditioned play audiometry (CPA) can be attempted. In this assessment, the audiologist teaches the child to drop a ball in a bucket (or engage in some other enjoyable activity) whenever he/she hears a tone.

Auditory Brainstem Response (ABR) and Auditory Steady State Responses (ASSR) testing. For infants under 6 months of age, or for older babies who cannot be successfully evaluated using behavioral audiometry described above, ABR testing is the most common method to assess the auditory system and determine the child's hearing ability. In this process, sensors are placed on an infant's head and different types of sound stimuli, varying in frequency and intensity, are presented through earphones and a bone vibrator.

A computer analyzes the hearing nerve's response to sound and the audiologist interprets these results. Infants need to be asleep during this procedure and for older babies, this may require sedation.
If that is the case, the evaluation would take place in a clinic or hospital setting. Auditory Steady State Response (ASSR) testing may be used as another means of assessing ear and frequency-specific thresholds. ASSR testing can also be used to assess auditory nerve function when no ABR is present.

Depending on the test battery and cooperation of the child, the evaluation may take 1-2 hours and may be completed in a single visit, or may require more than one session with the pediatric audiologist. When all needed testing has been completed, the audiologist will combine the information gained from the assessment battery into a report that describes the child's hearing status and outlines recommendations. The audiologist should also explain the results to the parents and provide additional guidance.

Be sure that you obtain a copy of the report, and that you understand the findings so that you can also support parents in taking the next step, particularly if a hearing loss is identified and further intervention is required.