Fitting Young Children with Directional Technology

Question

Answer

One of the major complaints of hearing instrument wearers is their ability to hear in noise. A mild sensorineural hearing impairment can severely reduce discrimination in noise, and greater degrees of hearing loss result in increasing degradations in performance. Studies show that infants and young children find it even more difficult than adults to understand in a noisy environment (e.g. in the kindergarten, playground, etc.) In order to provide our pediatric patients with a consistent, high-quality language input, we need to offer them access to technology that offers them solutions in noise.

An effective way to improve signal to noise ratio is the use of directional microphones. While this technology has been extremely successful in the adult population we now have evidence that children realize similar benefits once they are old enough to experience noise from the rear or each side. Gravel (1999) reported a mean improvement in signal to noise ratio of almost 5 dB for subjects age five to eleven using directional microphones. Although directional technology has proven benefits, it is also important to evaluate its use from a functional standpoint. Young infants that are not sitting up independently will typically not receive benefit from directional microphones. It is also important that children are given access to sounds from all directions since localization and lateralization are learned skills critical to a child's safety. A third consideration is that toddlers and young children will frequently not be oriented face-to-face with the primary speaker while noise is originating behind them. For these reasons it is important to incorporate a directional microphone as an optional program rather than a full-time setting.

The hearing instruments should be configured so that the parent can manually access a directional noise program through a switch on the instrument or a remote. In general children are able to switch between programs
independently from about 5-6 years of age. At this time it may be appropriate to enable an automatic feature that would turn on a directional microphone in noisy environments. It is important to counsel the caregivers about which situations could be improved with the use of the directional program. The advantage of digital instruments is that you have the most flexibility to incorporate features such as directional microphones over time in order to tailor the aid to the child's needs and optimize input in a variety of listening environments.

Christine Jones, M.S., CCC-A

Christine Jones joined the Phonak training team to focus primarily on pediatric amplification. Previously, she worked at a university hospital and a children's hospital performing diagnostic testing and fitting amplification on infants and children. She holds an M.S. from Vanderbilt University.

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