When I started fitting hearing instruments to children, almost 25 years ago, I felt excited by the challenge of helping them and their families and addressing their concerns about the future. Especially with the first hearing aid fitting, right after the diagnosis has been made, the family is trusting in their new audiologist’s competence to recommend the most appropriate hearing instrument - and to fit it well. Flexer et al. (2019) wrote that the pediatric audiologist has a critical role in educating families and, therefore, needs to be ever mindful of the desired outcome expressed by the family.
I could not agree more. I always found it worthwhile to spend some time explaining the hearing loss thoroughly and its implications in daily life, or better, in specific listening situations. I have often noticed that parents appreciate this as it helps them realize how important it is to not just trust in technology. They should understand the impact they can have by creating optimal listening environments for their children, since good hearing requires more than just putting on a device. As Beck et al. (2017) reminds us, hearing is acoustic access to the brain; it includes improving signal-to-noise ratios by managing the environment and using hearing technology. All caregivers involved are well advised to develop a sense for the complexity of the listening environments their child is in, for example, to detect unnecessary noise sources that can be switched off to maximize the benefits of hearing aids.
Generally, it is hard to predict the development of hearing abilities, speech development, or acceptance of the hearing instruments by the child. However, with the latest technological developments in hearing instruments, the starting point of the child’s hearing journey has never been better, I think. McCreery (2015), however, pointed out that research has shown that the benefit that children with hearing loss receive from their hearing aids is related to the quality of the hearing aid fitting provided, especially with more severe hearing loss. So, how can we achieve the highest quality hearing aid fitting?
Pediatric vs adult fittings
When it comes to pediatric fittings, we all know they differ a lot from adult fittings. For example, the child’s ear canal has a smaller volume than an adult canal, resulting in greater sound pressure at the eardrum (Feigin, 1989). Significant over- or under-amplification due to a failure to measure the level of hearing aid output in the child`s ear canal places the child at risk for further hearing loss and/or delayed communication development (Pittman, 2019). So, objective measures of hearing aid function (i.e., real-ear measures) are critical to the hearing aid fitting process in children of any age (Pittman, 2019).
Conducting real-ear measurements can be a challenge though as it requires a certain level of cooperation from the child and support from the parents to encourage the child to sit still for a while, to look into a certain direction towards the loudspeaker and to accept the gadget on, and in, the ear. Children are naturally uneasy and distracted since these measurements are likely performed by a person whom the child has never seen before and in an unusual environment (hospital). This can have a negative impact on the amount of time that one has to place the probe-tube, conduct the measurements, and possibly even do some fine-tuning.
The newest products, features, and tools
I believe that Bernafon offers the right tools to help hearing care professionals (HCPs) overcome all these fitting challenges. Bernafon has recently released their newest True Environment Processing™ hearing instrument family called Leox. Leox is available as a Super Power (SP) and Ultra Power (UP) BTE. This product family achieves sufficient amplification without discomfort. The Dynamic Feedback Canceller™, for example, is mind blowing to me as for the first time in my long career, I find it hard to force these power hearing aids into any feedback. Amazing, to say the least. Please bear in mind that this great feedback cancelling technology does not mean that old ear molds should be worn for longer. Children can grow so fast and many other things are important too (e.g., hygiene), so recommendations for the handling of ear molds remains the same.
The fitting software Oasisnxt provides full flexibility to the HCP to fit hearing instruments according to their client’s individual needs with the integration of real-ear measurements that can fine-tune the hearing aids automatically with certain IMC2-devices or to utilize real-ear-to-coupler-difference (RECD) values. Target match is facilitated with the REM AutoFit feature embedded into the fitting software. Implementation of the industry standard IMC 2 protocol enables compatibility and an easy connection to external diagnostic equipment from various major manufacturers. Additionally, the Audioscan VerifitLINK system is available for automated fit-to-target measures.
In any case, the child needs to accept at least one in situ measurement to evaluate his/her individual response of the ear canal. This might be particularly difficult during the first year of life, so simulated real-ear measurements might be the only option. Simulated real-ear measurements do allow precise shaping of the frequency response to the targets calculated by fitting protocols designed to provide children with sufficient audibility for optimal speech perception (Pittman, 2019).
Following best practice guidelines
In terms of fitting rationale, I like to stick to the American Academy of Audiology`s clinical practice guidelines for pediatric amplification, published in 2013 (Ching, et al., 2013). In compliance with these guidelines, Bernafon uses the validated, standard fitting rationale DSL v5.0 pediatric (Scollie, et al., 2005) as the default for fitting children and young adults. This fitting rationale is a pediatric-focused prescriptive formula that supports a normal loudness perception with audible and comfortable speech cues in all listening environments. These protocols are evidence-based, and deviation from them is not recommended (Pittman, 2019). DSL v5.0 pediatric provides one of the broadest aided speech spectrums with greater amplification than other fitting rationales as shown in Figure 1.
Figure 1: Overview of aided speech spectrums of different fitting rationales at 65 dB International Speech Test Signal (ISTS).
An advantage of DSL v5.0 pediatric and Oasisnxt is that targets can be calculated even with minimal audiological information. This becomes particularly helpful when a full hearing test cannot be conducted, a common challenge in pediatric audiological assessment. Especially for pediatric fittings, real-ear measurements should be obtained with any change in hearing, ear molds, or hearing aid settings. Aided thresholds can be added to confirm that the amplified signal is perceived at the level of the auditory cortex (Pittman, 2019).
To summarize, I can say that Bernafon`s fitting software Oasisnxt has a history of providing flexibility as well as optional automated tuning. Oasisnxt applies a simple and intuitive fitting flow to allow precise and user-specific fitting or fine-tuning. For pediatric fittings, it is common to implement real-ear data. Therefore, Bernafon`s Oasisnxt includes the option to enter measured RECD data to provide a more accurate fit.
The recently launched Leox Super Power and Ultra Power BTE hearing instrument is one of the most powerful pediatric hearing aids on the market with an incredible feedback canceller. Leox provides not just the amplification required, but also the state-of-the-art technology that is essential for adaptation of the devices to the changing needs of children throughout the various stages of their life.
Every child deserves the best start in life. Today, we have great fitting solutions and fantastic hearing instruments – let`s make sure that they fit.
For more information, go to the Leox 7|3 webpage and/or to the newest Topics in Amplification in our Library entitled “Leox for children and young adults”.
References
Beck D., & Flexer C. (2011). Listening in where hearing meets brain…in children and adults. Hear Rev, 18(2): 30-35. Retrieved from: http://www.hearingreview.com/2011/02/listening-is-where-hearing-meets-brain-in-children-and-adults/. Accessed November 29, 2017.
Ching, T., Galaster, J., Grimes, A., Johnson, C., Lewis, D., McCreery, R., . . . Yoshinga-Itano, C. (2013). American Academy of Audiology clinical practice guidelines: Pediatric amplification. Reston, VA: American Academy of Audiology.
Feigin, J. A., Kopun, J. G., Stelmachowicz, P. G., & Gorga, M. P. (1989). Probe-tube microphone measures of ear-canal sound pressure level in infants and children. Ear and Hearing, 10(4), 254-258.
Flexer, C., Madell, J. R., Wolfe, J., & Schafer, E. C. (2019). Why Hearing is Important in Children. In J. R. Madell, C. Flexer, J. Wolfe, & E. C. Schafer (Eds.), Pediatric Audiology (pp. 3-54). New York, NY: Thieme ISBN 978-1-62623-401-7.
McCreery R. W., Walker E. A., Spratford M., Bentler, R., Holte L., Roush P., . . . Moeller M. P. (2015). Longitudinal predictors of aided speech audibility in infants and children. Ear Hear, 36(Suppl 1): 24S-37S. doi: 10.1097/AUD.0000000000000211.
Pittman, A., & Beauchaine, K. L. (2019). Hearing Aids for Infants, Children, and Adolescents. In J. R. Madell, C. Flexer, J. Wolfe, & E. C. Schafer (Eds.), Pediatric Audiology (pp. 215-275). New York, NY: Thieme ISBN 978-1-62623-401-7.
Scollie, S., Seewald, R., Cornelisse, L., Moodie, S., Bagatto, M., Laurnagaray, D., . . . Pumford, J. (2005). The desired sensation level multistage input/output algorithm. Trends in amplification, 9(4), 159-197.