Visual Reinforcement Audiometry (VRA) is a behavioral hearing test designed for young children who are not yet able to participate in standard, verbal hearing assessments. This method is typically used for infants and toddlers between the ages of six months and two and a half years old. VRA uses the principles of operant conditioning to determine the softest sounds a child can hear by observing their natural head-turn response.
What VRA Is and Who It Is For
Visual Reinforcement Audiometry is a technique that capitalizes on a child’s natural tendency to turn their head toward an interesting sound source. The test relies on behavioral conditioning, where the child learns to associate hearing a sound with receiving a visual reward. This systematic approach allows audiologists to gather objective information about a child’s hearing sensitivity. The target age range for VRA is generally from six months up to approximately 30 months. Children in this developmental stage are too young for the standard pure-tone audiometry. The ultimate goal of VRA is to identify the minimum response level, or hearing threshold, at different sound frequencies to create a hearing profile.
The Step-by-Step Testing Process
The VRA procedure is conducted in a sound-treated booth, where the child is typically seated on a parent’s lap or in a high chair. The child is positioned at the center, facing a neutral, engaging toy or screen used to hold their attention between sound presentations. Speakers or transducers like insert earphones are used to deliver the sound stimulus and are placed to the child’s sides.
The test begins with a conditioning phase, which is the process of teaching the child the sound-reward association. A sound, such as a warble tone or a narrow-band noise, is presented at an easily audible level simultaneously with the activation of the visual reinforcer. The visual reinforcer is usually a darkened box that illuminates to reveal an animated toy or a video screen, which is positioned next to the sound source. The child learns that turning their head toward the sound source results in seeing the reward.
Once the child consistently turns their head in response to the simultaneous sound and visual cue, the testing phase begins. The audiologist presents the sound stimulus alone and observes the child’s spontaneous head turn. If the child turns their head toward the visual reinforcer immediately following the sound, the audiologist presents the reward as confirmation that the child heard the sound. The audiologist then systematically lowers the sound intensity in a descending-ascending method to find the softest level at which the child reliably responds.
Preparation and Understanding the Outcome
Parents can take steps to maximize the effectiveness of the VRA session, as the test relies heavily on the child’s alertness and cooperation. Scheduling the appointment around the child’s best time of day, often after a nap and a light snack, can help ensure they are engaged. During the test, the parent’s primary role is to remain silent and still, avoiding any subtle reaction or cuing, such as flinching or looking toward the sound source, which could influence the child’s response.
The results of the VRA test are documented on an audiogram, which is a graph that plots the child’s hearing thresholds across different sound frequencies. The threshold represents the quietest sound level, measured in decibels, that the child can hear at least 50% of the time. The audiologist uses these frequency-specific thresholds to determine if the child has normal hearing or if a hearing loss is present. If the results indicate a hearing loss, the audiogram provides the necessary data to guide further diagnostic testing or to plan for intervention, such as hearing aid fitting.