Dr. McCreery is associate director of audiology and staff scientist at Boys Town National Research Hospital in Omaha, NE.
Hearing-aid technology has evolved rapidly in recent years, making way for the development of devices that can be fit with minimal occlusion of the ear canal.
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Particularly for adults with high-frequency hearing loss and regions of normal low-frequency hearing, the ability to keep the ear canal open while providing amplification has changed the way we think about hearing aid candidacy.
Combined with the use of small, cosmetically appealing behind-the-ear cases, open-fit hearing aids have become increasingly popular for adults. The effectiveness and acceptance of open-fit devices in this age group has naturally led to questions about whether or not we should consider the same configuration for children.
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The size and appearance of a hearing aid can be important to parents and older children, but they should not be the determining factors in the style of hearing aid recommended. Open-fit hearing aids may be appropriate for children as long as the following primary goals of amplification are achieved.
* Audibility: Open-fit hearing aids should only be considered for children if the devices can provide adequate gain to make speech audible.Children are more likely than adults to experience fluctuation and progression of hearing loss. These fluctuations can be permanent or temporary. Open devices that can be converted to closed fittings through coupling to a regular earmold should be considered for children to avoid their being stuck with a device that provides inadequate audibility if hearing changes.
* Retention: Even keeping a standard behind-the-ear hearing aid coupled to a child's full-shell earmold can be challenging for parents. Many options that keep the ear canal open will result in difficulty with retention, particularly in infants and young children with very small ears.Hearing aids that don't stay on the ears can be lost or lead to parental frustration. Retention should be a key consideration in whether or not a child is a good candidate for an open-fit device.
* Verification: The real-ear-to-coupler difference (RECD) has become an important part of hearing aid verification in infants and young children. However, the RECD is based on the assumption that the ear canal is mostly occluded when the hearing aid is in place. It also can be difficult to attach an open-fit device to a hearing aid coupler.Given the limited options for RECD with open-fit devices, the hearing aid must be verified using in-situ probe microphone measures, which are often not easily obtained in young children. Selecting an open-fit hearing aid for a child means making a commitment to use real-ear verification instead of the real-ear-to-coupler difference.When this type of verification is not realistic, the clinician might consider a device that is initially coupled to an earmold but could be converted to open fit when in-situ verification is an option.
* Connectivity: Hearing assistive technology can give children access to listening and communication situations where hearing aids alone are not sufficient, such as classrooms, churches, theaters, amusement parks, and other public venues. Children are increasingly likely to use their hearing aids with smart phones, tablets, computers, gaming systems, and other technologies.The ability to connect to the listening situations that are most important to them can be a huge incentive for children to wear their hearing aids. Open-fit devices for these young patients should be widely compatible with hearing assistive technology and provide options for connectivity.If there are questions about compatibility, consult with the child's educational audiologist—if the child is lucky enough to have one at school or in the school district—prior to ordering the device.
IDENTIFYING THE RIGHT CANDIDATES
Given all of these considerations, when might open-fit hearing aids be an option for children?
The age of the child clearly stands out as an important candidacy consideration. If all the previously mentioned goals can be achieved, open-fit devices are potentially an excellent choice for some older school-age children and teenagers who have documented stable hearing thresholds and may be entering a phase where smaller, less occluding devices are more likely to be used consistently.
Adolescents and teenagers should be informed about the advantages and any limitations of open-fit devices. This information will help them select a hearing aid that has a style they find acceptable but will also help them hear across the widest range of environments and listening situations.
For several reasons, infants and younger children may be less likely than older children and adolescents to be good candidates for open-fit hearing aids.
With a shorter hearing history on which to base the potential for progression, plus a greater likelihood of fluctuations in hearing due to middle-ear problems, younger children need more flexibility in fitting range than older children do.
Parents of preschool children who were fit with minimally occluding devices at other clinics have reported frustration with limited battery life and retention, as well as concerns about durability.
Although acoustic feedback is much less of a concern now than it was even 10 years ago, issues with retention can result in frequent feedback, which can be a barrier for parents trying to establish consistent hearing aid use.
Without question, the ability to provide amplification and keep the ear canal as open as possible has been a fantastic development in hearing aid technology.
If the goals of providing audibility and promoting communication access across a wide range of situations can be met, open-fit devices may be an excellent solution for older children, adolescents, and teenagers.
While open-fit hearing aids may not be the most appropriate option for infants and younger children, the option of using a device that can be fit with a regular earmold and then later converted to an open-fit option can be an excellent compromise.
© 2014 by Lippincott Williams & Wilkins, Inc.