Foundations of Pediatric Audiology
RATING: (4 of 5 ears)
EDITORS: Fred H. Bess and Judith S. Gravel
PUBLISHER: Plural Publishing
REVIEWER: Jane B. Seaton, MS, Audiology and Communication Disorders Consultant, Seaton Consultants, Athens, GA
SYNOPSIS: Foundations of Pediatric Audiology is a collection of selected publications covering information that the authors consider critical to the understanding of fundamental principles for the practice of audiology with infants and children. Divided into five sections that target identification and assessment of young children, Bess and Gravel have included articles written by different authors that contain seminal historical research and address significant issues in clinical practice. Topics range from the development of audition in infants, assessment techniques and philosophies, models, technologies, controversies in newborn hearing screening, and special populations. The authors’ preface is critical for understanding their article selection process, and they have included brief overviews with suggested additional readings to introduce each of the five sections.
REVIEW: Section I: “Development of Auditory Function” includes readings from developmental psychoacoustics that may be unfamiliar to many pediatric audiologists but provide a critical framework of knowledge about the normal progression of auditory development in infants. Research is presented on threshold sensitivity in quiet and in noise, infant hearing sensitivity, auditory localization abilities, frequency resolution, and temporal resolution. This section concludes with two important studies on infant speech discrimination and the impact of linguistic experience on phonetic perception.
Section II: “Behavioral Methodology” begins with the classic James Jerger and Deborah Hayes paper that introduced the cross-check principle critical for pediatric clinical practice. Two subsequent articles provide information on behavioral observation audiometry (BOA) leading to the conclusion that accurate assessment of infants cannot be accomplished using unconditioned, observation methods. This is followed by investigations where outcomes support the effectiveness of cross-checking.
A series of five articles on pediatric speech detection and identification abilities completes Section II. Arthur Boothroyd describes several challenges in the measurement of speech discrimination, and proposes use of a phonemic scoring system to help address some of his concerns in this area. Mark Ross and Jay Lerman’s article describes the development of the Word Intelligibility by Picture Identification (WIPI) test, and this section concludes with a comparison of three widely-used pediatric instruments (the WIPI, PBK-50, and NU-6 tests), as well as a description of two highly useful speech identification tools for pediatric practice: the Bamford-Kowal-Bench Sentence Lists, and the Pediatric Speech Intelligibility test by James and Susan Jerger.
Section III: “Electrophysiologic/Physiologic Methodology” presents research in three broad categories: aural acoustic immittance, the auditory brainstem response (ABR), and evoked otoacoustic emissions (EOAEs). The importance of using these electrophysiologic tools for the cross-check principle (described in the previous section) is emphasized here. The first five articles address the history of “impedance audiometry,” beginning with early support for tympanometry as a simple, rapid, atraumatic, valid, and objective test for middle ear effusion in infants and young children. Normative data on tympanometric gradient for preschool children is presented next, followed by a paper on sensitivity and specifity of screening results with newborns. Recommended modifications of procedures and protocols are included in the three articles that follow. The fifth paper describes potential use of wide-band reflectance in newborn hearing screening.
Section III continues with articles on the auditory brainstem response (ABR), introduced by the classic 1977 article by A. Starr, R.N. Amlie, W.H. Martin, and S. Sanders that describes the development of these potentials in newborns. Michael Gogra’s paper further delineates maturational changes in absolute and interwave latencies for the pediatric population, and the subsequent report compares early click ABR results with later audiograms. Articles investigating the use of brief tones in notched noise and air, and bone-conducted click stimuli conclude that both of these procedures would be valuable additions in the assessment of infant hearing loss. A final paper describes the measurement of auditory steady-state evoked potentials in newborns and its potential use in neonatal hearing screening.
Section III concludes with reports on the use of EOAEs, including click evoked otoacoustic emissions (CEOEs) and distortion product otoacoustic emissions (DPOAEs) with infants and children. Susan Norton and Judith Widen deduce EOAEs tests have promise for clinical use, but these researchers raise several relevant questions for future investigation. A second paper reports on the combined use of DPOAEs, CEOEs, and ABRs for preterm and full-term infants.
Section IV: “Screening for Auditory Function” takes a somewhat different, albeit related, direction by including literature that discusses universal newborn hearing screening (UNHS) as a public health issue. Robert Turner proposes a cost-benefit model for use by audiologists in the selection of optimal early identification protocols. His paper is followed by an article reporting on the use of the ABR with babies from an intensive care nursery that identifies and discusses four challenges of this UNHS methodology--sensitivity, specificity, cost, and prevalence of later-confirmed hearing loss. Automated ABR, and otoacoustic emissions are presented in the next two articles, followed by a paper describing outcomes from a statewide multi-center UNHS demonstration project. The remainder of Section IV includes the original Fred Bess and Jack Paradise paper challenging the 1993 National Institutes of Health Consensus Statement recommendations for UNHS as being premature, costly, and unsubstantiated by rigorous outcomes research. Selected responses to this controversial paper follow, and will remind readers of the lack of consensus among audiologists at that time.
Section V, the final section of Foundations of Pediatric Audiology, begins with the now-classic overview of unilateral hearing loss in children by Fred Bess and Anne Marie Tharpe. Ira Ventry’s excellent critique of research on the effects of conductive hearing loss follows. Three subsequent articles on early otitis media in children remind us that, as yet, there are few clear answers on the long-term effects of this prevalent pediatric condition. The impact of minimal, higher-frequency sensorineural hearing loss on speech recognition in noise, and the oft-cited article by Fred Bess and colleagues covering prevalence, educational performance, and functional status of this pediatric population conclude this section.
CRITIQUE: Bess and Gravel have achieved their goal of compiling a representative sample of research that undergirds the practice of pediatric audiology. Foundations of Pediatric Audiology provides a wealth of information in a single source, although readers may wish space had allowed for the inclusion of additional commentary by these two eminent professionals. This publication is recommended as a supplementary text for coursework in pediatric audiology, and individual articles or sections as a whole, together with the authors’ suggested readings, should serve as a useful resource for more in-depth courses covering research and practice with specific technologies. Practicing clinicians would be well-served to have this single volume of readings on their shelf to provide research history and evidence-based support for the design and implementation of programs and protocols in the identification and assessment of hearing in infants and children.