Commentary on Pediatric Hearing Instrument Fitting Procedures: Honoring the Contributions of Denis Byrne

National Centre for Audiology
The University of Western Ontario, London
Ontario, Canada

A version of this Commentary was previously published in Audiology Insight. Bernafon AG, 2003.

In 1996, Denis Byrne published an article in the Journal of the American Academy of Audiology entitled, "Hearing Aid Selection in the 1990s: Where to?" (Byrne, 1996). Upon reading an early draft of this paper, I proposed to Denis that a better title might be, "Hearing Aid Fitting Procedures at the Crossroads." He kept the title as he had written it. Over the years, Denis and I communicated frequently, often sharing our concerns about developments in the field, about the future of hearing aid fitting procedures and, especially about issues related to hearing aid fitting in children. Denis and I did not always agree on the details. However, we always did share the same bottom line. His 1996 article was, of course, forward looking. It raised important issues that we have yet to resolve even now, some seven years later. It expressed a point of view, as only Denis could, that I share and shall discuss briefly within this commentary as a way to honor the important contributions Denis Byrne made to our field throughout his exemplary career.

Within this commentary I would like to present and briefly discuss five points that Denis and I had agreement on. We actually agreed on more than five, however, five is enough for one commentary.

1. The hearing health care professional is ultimately responsible for the accuracy and appropriateness of the hearing instrument fitting.

A current concern is that, in some settings, pediatric hearing instrument fitting is comprised of two steps: (1) entering several threshold estimates into a manufacturer's software system, and (2) selecting the ''quick fit' option. Unfortunately, there are a number of audiometric, acoustic and electroacoustic variables that may not be accounted for when this approach is taken - variables that are of particular importance in the fitting of amplification in infants and young children (Ching and Dillon, 2003; Seewald and Scollie, 2003).

2. The hearing health care professional must be able to verify the adequacy of the electroacoustic fit in a manner that is both comprehensive and valid.

Because of my interest in pediatrics, I am particularly concerned by some developments in our field that relate to this point. Recently, we have been told by some hearing instrument manufacturers that we cannot measure the electroacoustic performance of their high-end digital instruments in a valid way. Simultaneously we are told by these manufacturers that we should be fitting these instruments to infants and young children. From my perspective, this creates a serious ethical dilemma for the hearing health care professional. Regardless of the type of instrument that is to be fitted, it is the audiologist who is ultimately responsible for the appropriateness and accuracy of the fitting. The responsible audiologist wants to know as much as possible about the levels of amplified sound that are delivered into the ears of infants and children. To this end, the audiologist must apply comprehensive, evidence-based electroacoustic verification strategies that are compatible with the characteristics and capabilities of this unique population (American Academy of Audiology, 2003; Ching and Dillon, 2003; Scollie, 2003; Scollie and Seewald, 2002; Seewald and Scollie, 2003). This is an issue that requires immediate cooperative efforts between the hearing instrument industry and the profession.

3. The hearing instrument fitting process is comprised of a series of sequential and highly integrated stages, including assessment, selection, verification, and validation.

It is necessary that the procedures that are applied in this process be appropriate to the age and capabilities of the infant or young child under consideration and that it be systematically embedded within the more general program of audiologic habilitation. Anything less (e.g., omitting a step in the process) is simply incomplete and does not comply with preferred practice guidelines in our profession (e.g., American Academy of Audiology, 2003).

4. Whenever possible, hearing health care professionals should apply evidence-based procedures within the hearing instrument fitting process.

I doubt that anyone would argue with this point. As a field, however, we have not always approached the clinical fitting problem as scientifically as we could. There are, no doubt, several reasons for this - some good, some not so good. More and more, however, hearing health care professionals are being required to submit the scientific evidence in support of the procedures they apply. This is certainly the case in the Early Hearing Detection and Intervention (EHDI) programs now being implemented globally. ''Good ideas' without validating evidence are no longer sufficient and, within some jurisdictions, are unacceptable to those who now monitor and fund our hearing health care delivery systems.

5. Any hearing instrument fitting procedure that is proposed for clinical application should be open to scrutiny and fully understood before it is used.

This point takes me back to the mid-1980s when I can recall reading and re-reading Byrne and Dillon's paper on the new NAL-R procedure to ensure that I understood exactly what they were up to and why. Of course, as good scientists, they told us. And as a responsible clinician I wanted to know: What is the theory? What are the assumptions? What do the data tell us? What are the limitations? Where have all of these questions gone?

At a personal level, I have established three goals for the final years of my own career: (1) to participate in developing new knowledge in pediatric hearing instrument fitting where it is required; (2) to work cooperatively with others toward the development of a greater degree of consensus on what constitutes best practice in pediatric fitting; and (3) to find and implement more effective ways to bring what is already known into the everyday realities of audiologic service delivery to children and their families. I shall miss Denis' participation in these efforts. I shall miss his wisdom, his values and, most of all, his passion for doing it the right way.

Reference

American Academy of Audiology: Pediatric Amplification Protocol, Draft (July). American Academy of Audiology.

Byrne D. (1996) Hearing aid selection for the 1990s: Where to? Journal of the American Academy of Audiology, 7(5): 377-395.

Ching, T. and Dillon, H. (2003) Prescribing amplification for children: Adult-equivalent hearing loss, real-ear aided gain, and NAL-NL1. Trends in Amplification, 7(1): 1-9.

Scollie, S. (2003) Hearing aid test signals: What's new and what's good for kids. Hearing Journal, 56(9): 10,12,14-15.

Scollie, S. and Seewald, R. (2002) Electroacoustic verification measures with modern hearing instrument technology. In R. Seewald and J. Gravel (Eds.) A Sound Foundation Through Early Amplification: Proceedings of the Second International Conference. Phonak AG: Stafa Switzerland. 121-137.

Seewald, R. and Scollie, S. (2003) An approach for ensuring accuracy in pediatric hearing instrument fitting. Trends in Amplification, 7(1): 29-40.

Address Correspondence to:

Richard C. Seewald, Ph.D.
National Centre for Audiology
Elborn College
The University of Western Ontario
London, Ontario, Canada N6G 1H1

Email: Seewald@nca.uwo.ca
Phone: 519 661 2111 x88258
FAX: 519 661 3805

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