Authors:
Katz, Jack, Ph.D., University at Buffalo, SUNY, Buffalo, NY (contact jackkatz jackkatz@buffalo.edu)
Johnson, Cheryl DeConde, Ed.D., Colorado Department of Education, Denver, CO
Tillery, Kim L. Ph.D., SUNY College at Fredonia, Fredonia, NY
Bradham, Tamala, Ph.D., University of South Carolina, Columbia, SC
Brandner, Susan ,Au.D. Candidate, Audiology Associates of Freehold, Freehold, NJ
Delagrange, Teryl N, Au.D., Greensboro Ear, Nose & Throat Assoc., Greensboro, NC
Ferre, Jeanane M., Ph.D., Central Auditory Evaluation and Treatment, Oak Park, IL
King, John, M.Ed., University of Miami Ear Institute, Miami, FL
Kossover-Wechter, Denise, M.A., M. Ed., Legacy Good Samaritan Hospital, Portland, OR
Lucker, Jay R., Ed.D., Private Practice Specializing in Auditory Processing, Washington, DC
Medwetsky, Larry, Ph.D., Rochester Hearing and Speech Center, Rochester, NY
Saul, Richard S., Ph.D., Neuro-Audiological Associates of Boca Raton, Boca Raton, FL
Rosenberg, Gail Gegg, M.S., Interactive Solutions, Inc., Sarasota, FL
Stecker, Nancy A., Ph.D., University at Buffalo, SUNY, Buffalo, NY
Editor's Note - This article is an expanded version of the previously published "Clinical and Research Concerns Regarding the 2000 APD Consensus Report and Recommendations" (13 authors listed), published in Audiology Today, 14:2, March-April, 2002, pages 14-17.
Introduction:
In April 2000 Jerger & Musiek convened a conference of "14 senior scientists and clinicians... to reach a consensus on ... diagnosing auditory processing disorders1 [APD] in school-aged children" (Jerger & Musiek, 2000 p. 467). Six months later their article came out with their suggestions from their Dallas, Texas conference.
They indicated that APD screening "should include" two procedures, dichotic digits and gap-detection tests. In addition, they recommend that "in order to provide the minimum amount of information necessary" for evaluation of children, nine tests (or types of tests) should be administered, including: pure-tone thresholds, performance-intensity functions for word recognition, a dichotic task, duration pattern sequence, temporal gap detection, immittance audiometry, otoacoustic emissions, and both auditory brainstem response and middle latency response.
Because consensus conferences are generally helpful to professionals by offering clinical regimens based on strong research and clinical findings; we were pleased to learn of the Dallas conference. However, we believe Jerger & Musiek (2000) did not achieve the desired result. We have serious concerns about the basic philosophy of the article, the manner in which it was written, and most importantly the specific recommendations that were made.
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1 We have used the term auditory processing disorder (APD) to be consistent with Jerger & Musiek's terminology. This should not imply approval. Rather we believe that both the term and the definition they attach to it (see pp 467-8) should be carefully and critically considered.
Philosophy:
It is our belief, that the primary focus of Jerger & Musiek is almost exclusively geared to ruling out other problems when testing children seen for APD evaluations. Jerger & Musiek indicate that some of these children may have attention deficit hyperactivity disorder (ADHD), reading, language or learning problems, autism and/or reduced intellectual functioning leading to a misdiagnosis of APD.
Although it is true that audiologists need to be cognizant of problems masquerading as APD, the focus of the APD evaluation should not be limited to this narrow end. Some of these disorders may result from APD and therefore their presence might actually increase the likelihood of APD (ASHA, 1996).
We believe Jerger & Musiek missed the most important and likely reasons why a child is referred to the audiologist and is seen for APD testing. Specifically, the school and/or parents want to determine...
- Is an APD present?
- If so, what is the specific APD?
- What are the treatment options and recommendations?
On the other hand, the ASHA (1996) guidelines on Central Auditory Processing Disorders have much broader and, to our way of thinking, more appropriate goals. The ASHA (1996) guidelines indicates that one goal of the assessment is to develop an intervention program, "that will improve the everyday function and satisfaction of people who come to us for care" (p. 154). That is, an educational focus is needed for us to help these children and not simply a medical (diagnostic) focus that only informs us whether the child has an AP problem.
The procedures Jerger & Musiek recommend are too heavily oriented towards differentiating APD from other disorders, rather than describing the AP problems and seeking remedies. We are not aware of literature that shows a general problem with audiologists mislabeling children as APD (see Arnst, 1982; Musiek et al., 1991; Riccio et al., 1994; Tillery et al., 2000).
The Need to Reply to Musiek & Jerger, 2000:
A group of clinical/educational audiologists who look at APD primarily as a learning-communication problem (but surely do not ignore indications of neurological or other disorders) met at the American Academy of Audiology conference in San Diego, in April 2001 to discuss concerns and implications of the Jerger & Musiek article.
We were concerned that the Jerger & Musiek recommended approach places entirely too heavy emphasis on physiological measures and their extensive test battery would not be productive. In fact, we believe the Jerger & Musiek protocol would likely reduce the number of people seen for APD, given the length of the procedures, the associated costs and the restricted number of facilities that could provide such an extensive test battery. Jerger & Musiek voiced some of these same concerns.
Jerger & Musiek did not reference any statements in their article, so it was incumbent upon us to review their "suggested readings" and supplement them with other sources. We reviewed the specifically mentioned tests to see what literature we could find dealing with APD and normal-control children. We did not consider adult studies or those dealing with CNS lesions unless we did not find appropriate literature on APD in children.
Jerger & Musiek stated that their Minimal Test Battery (MTB) is the minimum required for proper APD testing of children. Therefore, we assumed they would designate only the strongest and most vital tests for this distinction. We further assumed that these tests would have a) appropriate norms, b) literature support dealing with the test population, c) sensitivity and specificity data, and d) been in common use by audiologists (i.e., clinically validated). This was not the case.
Because the Dallas conference was held in April 2000 we researched literature up to and including April 2000. Literature published after that time would not have entered into the participants' deliberations.
Procedural Concerns:
Jerger & Musiek's guidelines do not include bibliographic references. Therefore, it is difficult for the reader to know which statements are supported by research and which are simply the opinions of the authors. We recommend that the authors indicate which of the 55 suggested readings (or other supporting documents) they used as the basis for their various recommendations and to clearly label which are simply their opinions. In a scientific or professional article, no less a consensus statement, the absence of full citations is unacceptable and to our knowledge, without precedent.
Another concern is that the authors indicate they held a consensus conference. A 'consensus' implies, and should take into account, differing points of view. Although all members of the panel may be highly qualified professionals, they appear to over-represent certain groups while omitting others.
For example, educational audiologists are those most likely to be involved in screening, diagnosing and remediating APD in children and yet they were not included among the contributors.
Professional Concerns:
One drawback in the approach advocated by Jerger and Musiek is that most of the tests they specifically named are not widely used by audiologists2 and have limited value in programming for children who have APD. Thus, they have chosen tests with unknown clinical usefulness and without consideration for what to do about it. Such a proposed "medical model" approach does not address the learning problems that generally bring the children to us for help.
In presenting their MTB, Jerger & Musiek state, "the set of procedures listed below is suggested as the minimum necessary test battery". However, "Some clinicians may choose to carry out additional testing" (p. 471). Thus, we are to believe that these tests are essential for all children evaluated for APD, but that it would be acceptable to add even more procedures to this extensive test battery.
With regard to screening tests (and presumably tests for the MTB), Jerger & Musiek indicate they should meet, "acceptable psychometric standards ... [including] sensitivity and specificity, the predictive values of positive and negative results, inter-observer reliability intertest consistency and validity" (p. 469).
We believe that none of the tests they specifically recommended meet these criteria.
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2 Since the publication of Jerger & Musiek (2000) the use of these tests has increased presumably because many audiologist have attempted to comply with their recommendations.
Basic Audiometric Evaluation:
We have no argument with Jerger and Musiek's recommendations for pure-tone threshold, word recognition scores at PB-Max, and immittance audiometry. These tests serve a functional purpose in an AP test battery and are well accepted by audiologists (Martin et al., 1998 p. 96-97). However, the rest of the proposed evaluation measures deserve more careful scrutiny.
Physiologic Measures:
We found no research to show that physiological measures, such as those recommended by Jerger & Musiek, play an important role in the diagnosis of typical cases seen for AP testing. We have serious concerns with all three physiological tests they recommended.
- Otoacoustic Emission (OAE).
There is literature dealing with lack of suppression of OAEs in cases with central lesions. However, Jerger & Musiek do not recommend OAEs for suppression, rather they indicate this test should be used routinely in the APD battery because it is, "useful in ruling out inner ear disorders" (p. 471). We know of no literature to suggest that children with APD have a high risk of inner ear pathology. In fact, for general purposes pure-tone thresholds will demonstrate a sensorineural hearing loss at lower levels than are required to show inner ear pathology by OAEs. If they had recommended that all children with sensorineural losses (of 30dB or greater) be tested with OAEs, this could be justified. But testing all children seen for APD evaluations for inner ear pathology, regardless of hearing loss is difficult to comprehend.
To assess the potential value of Jerger & Musiek's recommendation of using OAEs for routine use, Katz & Amorim (2001) studied 150 randomly selected files of cases that were seen for APD testing. They found no child in that group to exhibit a sensorineural loss of >30dB HL at any frequency. Kemp (1978) indicates that OAE are not sensitive to inner ear losses of less than 30dB HL.
Martin et al. (1998 p. 100), stated that only 11% of audiologists use OAEs primarily for diagnostic purposes of any sort. Therefore, very few of the 11% would use OAEs to identify inner-ear pathology in the absence of a sensorineural hearing loss in these children. Because a) there is an absence of literature indicating the importance of OAEs with typical APD cases, b) most children who are seen for APD do not have significant sensorineural hearing losses (>30dB), c) OAEs are used by a very small percentage of audiologists for APD evaluations, and d) OAEs offer little information for assisting children with their processing deficits, the recommendation of OAEs as part of the MTB appears entirely unnecessary or at best, extremely premature.
- Auditory Brainstem Response (ABR).
- ABR and Middle Latency Response were recommended because they are, "key measures of the status of auditory structures at brainstem and cortical levels" (p. 472). We attempted to find ABR literature dealing with children who have APD, but were unable to locate any use of it with this population except in special cases. Therefore we know of no support for ABR as part of the MTB. Additionally, ABR is costly, time consuming, and difficult to administer to many children (e.g., with ADHD).
- Middle Latency Response (MLR).
- As in the case of the other tests, Jerger & Musiek provide no literature support for the use of MLR. In fact, in the study most closely associated with children and APD, Kraus et al. (1985) found no MLR differences between control children and those who had learning disabilities, language delays, mental retardation, or multiple handicaps. They also point out that there is much variability in results until about 10 years of age and that MLR can be influenced by many factors.
Jerger & Jerger (1985) report on four cases with CNS disorders (e.g., multiple sclerosis). Three of them had abnormal MLR results but all had abnormal results on their behavioral central test. They state, "Our enthusiasm for the clinical application of middle and late potentials must be tempered, however, by the divergence of opinion about the stability of these potentials as a function of age and test condition" (p. 35).
Jerger & Jerger also point out that, "Testing subjects in the sedated state is helpful in controlling the contaminating influence of myogenic activity ... however, reliability and stability of the MLR response seems to be affected. In our experience, subject state substantially affects the detectability of the MLR." Therefore, MLR has extremely limited application for evaluating children referred for AP testing, especially if sedation is called for.
Recently, Chermak & Musiek (1997) indicated that MLR is "new and partially experimental" (p. 138) even in patients with CNS disorders. Musiek et al. (1999) pointed out that, "... this range of amplitude differences seems to hold promise as criteria for clinical use, the high degree of variability found in patients [adults] with CNS lesions argues for more data" (p. 130). In children with APD we would expect fewer hits and more variability associated with age effects.
We found no research on MLR that provides a justification for including this test in a Minimal Test Battery. Specifically, the test a) is not very sensitive even in cortical lesion cases and shows great variability in normals, b) use with young children under age 10 is questionable especially if sedation is called for, c) is not widely used in audiology in general, no less for testing children with APD, and d) it is not clear how MLR would contribute to making appropriate recommendations when a child failed the test. Therefore, we find no justification for including MLR as part of a Minimal Test Battery.
Behavioral Measures:
Jerger & Musiek list the following four behavioral tests as part of their Minimal Test Battery.
1- Performance-Intensity Word Recognition. Jerger & Musiek state that performance-intensity tests are "essential for exploration of word recognition over a wide range of speech levels and for comparing the performance on the two ears" (p. 471). However, we found no research showing its application for evaluating APD. Without literature support for its effectiveness/usefulness, or even normative data for APD, it is difficult to see how this test could be considered part of the Minimal Test Battery.
2-Dichotic Digits (DD). Jerger & Musiek include dichotic digits as one of the two screening tests for APD and also as part of the Minimal Test Battery. The one study we found using this test with children was Musiek et al. (1982). They administered a number of central tests including Dichotic Digits to 22 children (8 to 10 years of age) who were thought to have APD. They found the Frequency Patterns test and Competing Sentences test (not Dichotic Digits) the most promising screening procedures in their study. The hit-rate for the Dichotic Digits test was only about 65%, which would not appear consistent with their stated goal for screening tests. They state, "... the goal of screening is to identify as many children as possible who may have APD, screening tests are purposely designed for maximal sensitivity" (p. 468). In order to achieve this, they say, it may be necessary to have a high false-positive rate. This does not coincide with a sensitivity rate of 65% reported by Musiek et al. (1982) and no false-positive information was given.
The other studies we found using DD dealt with adults who had primarily CNS lesions. Musiek et al. (1991) carried out a study of adults with cochlear or central lesions using the DD test. The hit rate in these CNS lesion cases was 75%, which appears reasonable with the 65% found in APD cases. The authors concluded, "Although more clinical research (especially prospective studies) must be done on DDT ... it appears to have potential value as an audiological screening test for CANS involvement" (p. 113). We could not find the additional CNS lesion research they said was needed. But more importantly we found no additional support for its use with children seen for APD.
Another serious concern with the Dichotic Digits test is the norms. Musiek, in the DD tester's instructions states, "We strongly recommend that you collect your own norms in your own area." (p. 2). Norms questioned by their author would be a serious limitation for any test and it is surely inappropriate for a test that is proposed as a standard test for all APD cases. If clinicians are expected to collect their own norms, then they would also need to gather the sensitivity-specificity data that Jerger & Musiek indicate is necessary to determine if the test meets acceptable psychometric standards.
The DD test does not meet any reasonable standard for the Minimal Test Battery, nor as a necessary screening tool. Although it has some positive features (as do other AP tests that were not mentioned in the Jerger-Musiek article), it does not have a) strong literature support, b) national norms, c) "acceptable psychometric standards", and d) no norms, of any sort, are reported below seven years of age.
Duration Pattern Sequence:
There is little research to elevate Duration Patterns to the level of Minimal Test Battery stature. In fact, we found no available literature using it for children with APD and based on Martin et al. (1998), there was little use of the test among audiologists. The single reference provided by the tester's instructions accompanying the test tape is Musiek et al. (1990). That study was carried out with brain and cochlear lesion cases and not with children with APD. No norms are offered to evaluate children for APD. We find no support for including Duration Pattern Sequence as part of a Minimal Test Battery.
Temporal Gap Detection:
Jerger and Musiek specify a temporal gap detection test using broadband noise as one of the two screening procedures and also as part of the Minimal Test Battery. Despite the importance they place on this procedure, we are not aware of any such commercially available test. If there is literature using this test for APD assessment we did not find it in the suggested readings or in our literature search.
Although Jerger & Musiek specified that the test should have "a short silent gap [that] is inserted in a burst of broad-band noise" (p. 469), only a pure-tone Auditory Fusion Test - Revised (McCroskey & Keith, 1996) is commercially available, but apparently this is not the test they suggest. Because there is no such test commercially available, and no norms, the test cannot be part of the Minimal Test Battery unless each audiology center produces its own test, gathers the norms, and demonstrates that their procedure has acceptable "sensitivity and specificity ... and validity" (Jerger & Musiek, 2000, p. 469). Clearly the Temporal Gap Detection test described by Jerger & Musiek does not meet any of their stated criteria.
Discussion:
By Jerger & Musiek's own standards (p. 469), not one of the tests that they specifically recommend should be part of the Minimal Test Battery or used as the critical screening tests for APD (see Table 1).
We believe that, at a minimum, any recommended procedure must be validated on children with APD and have age-appropriate norms.
We should also recognize that for the majority of children, our primary goal is to assess and improve their learning and communication abilities, rather than to determine if pathology or physiological variations are present. Therefore assessment batteries for AP should consider the learning and listening abilities of children.
In conclusion, we feel that although the consensus conference of Jerger & Musiek may have been well intentioned, it had a seriously limited focus, too many like-minded participants, an absence of educational audiologists, did not concern itself with the application to communication and learning in children, and was carried out too quickly and without sufficient deliberation, oversight and peer review.
After a detailed study of the tests they recommended for evaluation of APD in children, we found a) almost no literature using these tests with the target population, b) an absence of normative data for the tests, c) a lack of sensitivity and specificity data, and d) no evidence that the physiological tests are useful or appropriate as part of a Minimal Test Battery.
Further, such an extensive, time consuming test battery with little practical information would likely have the unintended consequence of removing audiologists from doing APD evaluations.
Furthermore, we believe that until a broad-based APD consensus conference is held, that is carefully peer reviewed by clinicians and researchers with APD experience and expertise, we consider the ASHA (1996) consensus statement the best available guideline.
1 Musiek, Geurkink, Kietel (1982), sensitivity = 65%, no specificity data available
2 Tester's Manual indicates, "norms are offered only as a guide...strongly recommend that you collect your own norms..." p. 1
3 Chermak & Musiek (1997) discussed noise suppressed OAEs, no support for regular OAEs
References:
Arnst, DJ (1982) SSW test results with peripheral hearing loss. In DJ Arnst & J Katz (Eds) The SSW Test: Development and Clinical Use. College-Hill Press: San Diego, CA., 287-293.
American Speech-Language Hearing Association Task Force on Central Auditory Processing Consensus Development (1996). Central auditory processing: Current status of research and implications for clinical practice. Amer J Audiol, 5 (2): 41-54.
Auditec (undated instruction sheet) Duration Pattern Sequence, 1 page.
Chermak, G.D., Musiek, F.E. (1997). Central auditory processing disorders: New perspectives. San Diego: Singular Publishing Group: San Diego, CA.
Jerger, J, Musiek, F (2000) Report of the Consensus Conference in the diagnosis of auditory processing disorders in school-aged children. JAAA 11, 467-474.
Jerger, S, Jerger J (1985) Audiological applications of early, middle and late auditory evoked potentials, Hearing Journal, 38, 31-36.
Katz, J, Amorim, PM (2001) Puretone thresholds in children seen for CAP testing. SSW Reports, 23, 16-17.
Kemp DT (1978) Stimulated acoustic emissions from within the human auditory system. Acoust Soc Am; 64: 1386-1391.
Kraus N, Smith D, Reed N, Stein L, Cartee C (1985) Auditory middle latency responses in children: Effects of age and diagnostic category. Electroencephalography and Clinical Neurophysiology, 62, 343-351.
Martin, FN, Champlin, CA, Chambers, JA (1998) Seventh survey of audiometric practices in the United States. Journal American Academy of Audiology, 9, 95-104.
McCroskey RL, Keith, RW (1996) Auditory Fusion Test - Revised: Instruction and User's Manual. Auditec of St. Louis: St. Louis, MO.
Musiek, F (undated tester's instructions) Instructions and Background for the Dichotic Digit Test, 1-2.
Musiek, F Baran, J, Pinheiro, ML. (1990) Duration pattern recognition in normal subjects and patients with cerebral and cochlear lesions. Audiology, 29:304-313.
Musiek, F, Charette, L, Kelly, T, Lee, W, Musiek, E (1999) Hit and false-positive rates for the middle latency response in patients with central nervous system involvement. JAAA, 10, 124-132.
Musiek, F, Geurkink, AN, Keitel (1982). Test battery assessment of auditory perceptual dysfunction in children. Laryngoscope, 92: 251-257
Musiek, F, Gollegly, K, Kibbe, K, Verkest-Lenz, S. (1991) Proposed screening test for central auditory disorders: Follow-up on Dichotic Digits test. The American Journal of Otology, 12 (2), 109-113.
Riccio, CA, Hynd, GW, Cohen, MJ, Hall, J, Molt L (1994) Comorbidity of central auditory processing disorder and attention-deficit hyperactivity disorder. Journal American Academy Child Adolescent Psychiatry, 33, 6, 849-857.
Tillery KL, Katz, J, Keller W (2000) Effects of methylphenidate (RitalinTM) on auditory performance in children with attention and auditory processing disorders. Journal Speech-Language and Hearing Research, 43 (4), 893-901.
