Acoustic-Immittance Characteristics of Children with Middle-ear Effusion : Longitudinal Investigation

Transcription

1 J Am Acad Audiol 6 : (1995) Acoustic-Immittance Characteristics of Children with Middle-ear Effusion : Longitudinal Investigation Carol A. Silverman*t Shlomo Silmant$ Abstract The purpose of this investigation was to describe, in a longitudinal prospective study, the acoustic-immittance profile during sessions with effusion and during sessions without effusion in children with recurrent middle-ear effusion (MEE). The static-acoustic middle-ear admittance, tympanometric width (TW), tympanometric peak pressure (TPP), and ipsilateral acoustic reflex (IAR) were evaluated in 36 ears of 18 children with recurrent MEE and 24 ears of 12 children without a history of MEE. Recurrent MEE was operationally defined as MEE diagnosed by microtoscopy and/or pneumotoscopy at four or more sessions over the first year of investigation. Subjects in the recurrent MEE group were followed over a time span of 1.1 to 3.0 years with an average intersession interval of 3.0 months. The results revealed that MEE was present at 78.3 percent of the sessions. A pure-tone average (PTA) exceeding 25 db HL was present at 80 percent of the effusion sessions in the recurrent MEE group. The false-alarm rate for each of the individual acoustic-immittance measures, especially the TPP and IAR, was markedly higher during the otoscopically normal sessions of the recurrent MEE group than in the control group. This suggests that even when MEE is absent at a particular session, recurrent episodes of MEE appear to alter the acoustic-immittance characteristics of the middle ear. Negative findings on all or three of the four acoustic-immittance measures occurred in only 1 percent of the effusion sessions in the total recurrent MEE group as compared with 76 percent of the normal sessions in the control group. Positive findings on all of the acoustic-immittance measures occurred in nearly 50 percent of the effusion sessions in the total recurrent MEE group as compared with only 3 percent of the normal sessions ire the control group. Key Words: Acoustic-immittance, acoustic reflex, hearing sensitivity, middle-ear effusion (MEE), recurrent middle-ear effusion, serous otitis media, static-acoustic middle-ear admittance, tympanometric peak pressure (TPP), tympanometric width (TW) n acoustic-immittance profile for children with middle-ear effusion (MEE) A was provided by Silman et al (1992) in their investigation of 82 middle ears with effusion and 53 middle ears without effusion. Silman et al evaluated the sensitivity and specificity for each single acoustic-immittance measure (static-acoustic middle-ear admittance [static], "Communication Sciences Program, Hunter College, CONY, New York, New York ; tdepartment of Speech and Hearing Sciences, Doctoral Program, Graduate School and University Center, CUNY, New York, New York ; and $Department of Speech, Brooklyn College, CUNY, Brooklyn, New York Reprint requests : Carol A. Silverman, 625 Main St., Apt. 1041, New York, NY tympanometric width [TW], tympanometric peak pressure [TPP], and ipsilateral acoustic reflex [IAR]), the ASHA (1990) acoustic-immittance protocol, and the Silman et al acoustic-immittance protocol. (The ASHA protocol is failed if either the TW is wide or the static is reduced ; the Silman et al protocol is failed if the IAR is failed along with a positive result on another acoustic-immittance measure.) The sensitivity and specificity were based on data collected from a single test session for each subject. Silman et al's study did not control for history of recurrent MEE. Utech Smith et al (1993) also reported on the sensitivity and specificity of a protocol based on a positive result on two acoustic-immittance measures (static and contralateral acoustic reflex

2 Journal of the American Academy of Audiology/Volume 6, Number 4, July 1995 vs static and TW) in children with MEE. The Utech Smith et al investigation was presumably based on children with recurrent MEE, as the data were collected just prior to surgery. Their investigation, however, was not longitudinal. Boe et al (1993) also investigated the sensitivity and specificity of the individual acousticimmittance measures and some of the two-measure combinations of acoustic-immittance measures in children with MEE; their study did not control for history of recurrent MEE and was not longitudinal. To our knowledge, no longitudinal investigations of each of the four acoustic-immittance measures have been done in children with recurrent MEE. Our own anecdotal data suggest that the acoustic-immittance findings of children with recurrent MEE at a test session where effusion is absent differs from those of normal children with a negative history of MEE. That is, there appears to be a higher frequency of occurrence of positive findings on each of the acoustic-immittance measures in children with recurrent MEE when effusion is absent than in children with a negative history of MEE. Prospective research on the sensitivity and specificity of the acoustic-immittance measures, singly and in combination, in children with recurrent MEE, based on serial acoustic-immittance assessment would yield an acoustic-immittance profile of children with recurrent MEE at sessions without versus with effusion. Further, no longitudinal investigations of the pure-tone average (PTA) have been done in children with recurrent MEE. The hearing sensitivity in children with recurrent MEE has not been followed long term over test sessions without MEE versus sessions with MEE. Silman et al (1994) investigated the air-conduction thresholds of children with MEE at the initial test and retest at 6 weeks post initial test. They found that the air-conduction thresholds worsened from initial test to retest in the group that passed a pure-tone screen at the initial test and improved from initial test to retest in the group that initially failed a pure-tone screen. The fluctuating nature of MEE underscores the need to examine the acoustic-immittance measures and hearing sensitivity in children with recurrent MEE at sessions without effusion as compared with the sessions with MEE. Studies documenting the frequency of occurrence of sessions with versus without MEE in children with recurrent MEE also are lacking. Jerger (1970) concluded that acoustic-immittance findings in combination have greater predictive accuracy than the individual acousticimmittance results. This was corroborated by Silman et al's (1992), Utech Smith et al's (1993), and Boe et al's (1993) findings of higher sensitivity and specificity for detection of MEE for a protocol based on failure of the acoustic reflex along with failure on another one of the acoustic-immittance measures (yielding failure on at least two measures), rather than a protocol (e.g., ASHA, 1990) based on failure of the TW and/or static (yielding failure on at least one measure). Research is lacking, however, on the sensitivity and specificity of one versus two versus three versus four acoustic-immittance measures for detection of MEE. Therefore, the purpose of this longitudinal investigation was to prospectively evaluate the sensitivity and specificity of the acoustic-immittance measures, individually and in combination, in children with recurrent MEE to establish an acoustic-immittance profile for the sessions with versus without MEE. Subjects METHOD Thirty-six ears of 18 subjects (9 boys and 9 girls) with recurrent MEE ranging in age from 3 to 9.6 years (mean = 5.0 years) at the onset of the study and 24 ears of 12 subjects (7 boys and 5 girls) without MEE ranging in age from 4 to 8 years (mean = 6.1 years) at the onset of the study were prospectively investigated. The subjects were drawn from an otolaryngologic center in New York City. The otologic diagnosis was established by a pediatric otolaryngologist with more than 15 years of diagnostic and middle-ear surgery experience using pneumotoscopy ; microtoscopy also was employed whenever the results of pneumotoscopy were questionable. The recurrent MEE subjects were referred to the center because they failed the school hearing-screen test or because the parent or teacher suspected a middle-ear problem. The normal subjects were referred to the center because audiologic and otolaryngologic examinations were required by the New York City Board of Education prior to entering school or transferring between schools. Recurrent MEE was operationally defined as MEE diagnosed by microtoscopy and/or pneumotoscopy at four or more sessions over the first year of investigation. Subjects with recurrent MEE were followed until three sessions with normal otologic findings were obtained or until they were lost to follow-up. Data from subjects with 340

3 Acoustic-immittance Characteristics of Children/Silverman and Silman recurrent MEE were drawn from subjects whose parents refused ear surgery or were drawn during the presurgical phase in subjects who received myringotomies with pressureequalization (PE) tubes. Data from the postsurgical phase of subjects who received myringotomies with PE tubes were excluded to control for the possible contaminating effect of ear surgery on the acoustic-immittance measures. Myringotomies with PE tubes were performed in 7 of the 18 subjects with recurrent MEE. The normal subjects had normal otolaryngologic findings (microtoscopy and/or pneumotoscopy), pure-tone thresholds not exceeding 20 db HL at 250 to 8000 Hz at each session, negative history of hearing loss and ear problems between sessions over the period of investigation, and negative history of MEE prior to the investigation. Instrumentation Audiologic assessment was carried out in an audiometric test room meeting ANSI S maximum permissible ambient noise levels for ears uncovered testing from 125 through 8000 Hz (ANSI, 1991). See Silman et al (1992) for a description of the acoustic-immittance instrumentation and calibration. Procedure The data were collected prospectively. Each subject was seen for a complete otolaryngologic evaluation immediately prior to a complete audiologic evaluation at the same session (test and all retests). The otolaryngologic evaluation included microtoscopy and/or pneumotoscopy. The audiologic evaluation included pure-tone air- and bone-conduction thresholds, SRTs and suprathreshold monosyllabic word-recognition assessment whenever possible, static assessment, acoustic-admittance pressure function, and ipsilateral acoustic-reflex-threshold (ART) testing (1000-Hz tonal activator). A blind design was employed. The otolaryngologic diagnosis was reached without knowledge of the audiologic findings, and the audiologic testing was performed without knowledge of the otolaryngologic findings at the initial test and all subsequent retests. If MEE was present, the otologic recommendation was audiologic and otolaryngologic retesting in 1 month if the PTA, based on 500, 1000, and 2000 Hz, exceeded 35 db HL and in 2 months, otherwise, provided bacterial infection or inflammation was absent. The otologic recommendation unavoidably placed a limitation upon selection of intertest interval. The number of test sessions with MEE over the duration of the study, rather than intertest interval, however, was the variable of interest in this investigation. Subjects with recurrent MEE were followed until (a) MEE was absent at three consecutive sessions, (b) they were lost to follow-up due to attrition, or (c) this report. If MEE was absent, subjects were invited to return for retesting at 3-month intervals until (a) the parents declined, (b) they were lost to follow-up due to attrition, or (c) completion of this report. RESULTS he number of test sessions per subject in the T recurrent MEE group ranged from 4 to 10 (mean = 5.9 sessions). In the normal group, the number of test sessions per subject ranged from 3 to 6 (mean = 4.5 sessions). Subjects in the recurrent MEE group were followed over a time span of 1.1 to 3.0 years (mean = 1.7 years). (The investigation was begun 3 years prior to this report.) Subjects in the normal group were followed over a time span of 1.0 to 2.6 years (mean = 1.5 years). The intersession interval ranged from 1 to 11 months (mean = 3.0 months) in the recurrent MEE group and 2 to 13 months (mean = 3.8 months) in the normal group. The total number of sessions across the 18 subjects with recurrent MEE was 212. Of the 212 sessions, 78.3 percent (166) were characterized by the presence of MEE and 21.7 percent (46) were characterized by the absence of MEE. The total number of sessions (normal) across the 12 subjects without MEE was 108. Table 1 shows the proportion and percentage of normal versus MEE sessions with positive findings on one or more acoustic-immittance measures or protocols, or on the PTA in the recurrent MEE and normal groups. Inspection of this table reveals that, in the recurrent MEE group, for the individual acoustic-immittance measures, the hit rates exceeded 95 percent for the tympanometric peak pressure (TPP) and JAR. The hit rate was very low (55%) for the static. The data in Table 1 also show that the sensitivity of the PTA was intermediate between the static, TW, and ASHA(1990) acoustic-immittance protocol, on the one hand, and the TPP, JAR, and Silman et al (1992) acoustic-immittance protocol, on the other hand. The sensitivity of the Silman et al acoustic-immittance protocol, which was essentially equivalent to that of the IAR, was notably

4 Journal of the American Academy of Audiology/Volume 6, Number 4, July 1995 Table 1 Proportion and Percentage of Normal versus MEE Sessions with Positive Findings on an Acoustic-immittance or Hearing Loss Measure in the Recurrent* MEE and Normal Groups Medical Diagnosis Low Statict Large TWt TPP* Elevated IAR Fail ASNA Protocol** Fail Silman et al Protocoltt Hearing Loss`# Recurrent MEE Group Normal Session 16/46 13/46 23/46 31/46 16/46 14/46 4/46 35% 28% 50% 67% 35% 30% 9% MEE Session 91/ / / / / / /166 Normal Group 55% 73% 98% 97% 77% 97% 80% 21/108 26/108 23/108 17/108 32/108 7/108 0/108 19% 24% 21% 16% 30% 6.5/o 0% TW = tympanometric width ; TPP = tympanometric peak pressure ; IAR = ipsilateral acoustic reflex. *Ears with MEE at four or more sessions during the first year of investigation as determined by microtoscopy and/or pneumotoscopy ;?static less than 0.35 mmho ; ttw greater than 180 dapa ; "TPP less than or equal to -100 dapa ; ipsilateral ART greater than 110 db HL or absent ; "static less than 0.35 acoustic mmho or TW greater than 180 dapa ; ttipsilateral ART greater than 110 db HL (or absent) with a TPP less than or equal to-100 dapa, ipsilateral ART greater than 110 db HL (or absent) with a static less than 0.35 mmho, or ipsilateral ART greater than 110 db HL (or absent) with a TW greater than 180 dapa, and "PTA (based on SOO, 1000, and 2000 Hz) greater than 25 db HL. higher than that of the ASHA acoustic-immittance protocol. These findings corroborate the results of Silman et al (1992) for their total MEE group based on one session per subject. Further inspection of Table 1 indicates that the false-alarm rate (based on the findings during the normal sessions) for an individual acousticimmittance measure in the recurrent MEE group was highest (67%) for the IAR. and lowest (28%) for the TW These findings are clinically significant. In this group, the false-alarm rates were similar for the ASHA (1990) and Silman et al (1992) acoustic-immittance protocols but slightly exceeded the best false-alarm rate for an individual acoustic-immittance measure. The falsealarm rate of the PTA (9%) was markedly lower than that for any individual acoustic-immittance measure or acoustic-immittance protocol. Table 1 further shows that the false-alarm rate for an individual acoustic-immittance measure in the control group was best for the IAR and worst for the TW although the range in false-alarm rates among the individual measures was only 8 percent. The false-alarm rate of the Silman et al (1992) acoustic-immittance protocol (6.5%) was lower than for any individual acoustic-immittance measure and was markedly lower than that of the ASNA (1990) acoustic-immittance protocol ; these findings are essentially similar to those reported by Silman et al (1992). The false-alarm rate was essentially nonexistent at 0 percent for the PTA. Comparison of the false-alarm data for the recurrent MEE versus normal groups shows that for each acoustic-immittance measure, acoustic-immittance protocol, and PTA, lower rates were obtained for the control group than recurrent MEE group. This difference in falsealarm rates was especially pronounced for the TPP and IAR. Thus, although the hit rates of the individual acoustic-immittance measures and protocols for the recurrent MEE group (multiple sessions per subject) are similar to those reported by Silman et al (1992) for the MEE group (one session per subject), the false-alarm rates for the recurrent MEE group, based on the otoscopically normal sessions, are substantially higher than those for the control group. These findings are clinically significant. Table 2 shows the percentage of (a) MEE sessions with positive findings on zero, one, two, three, or four individual acoustic-immittance measures in the total, recurrent MEE group and normal-hearing (PTA <_ 25 db HL), recurrent MEE group ; and (b) normal sessions with positive findings on zero, one, two, three, or four individual acoustic-immittance measures in the control group. In the total, recurrent MEE group, four acoustic-immittance measures were positive in nearly half of the MEE sessions. Positive findings on two or more individual acousticimmittance measures were obtained on 99 percent of the MEE sessions. Positive findings on only one acoustic-immittance measure was rare at 1 percent. Further, not a single MEE session was characterized by negative findings on all acoustic-immittance measures in this group. When only one acoustic-immittance measure 342

5 Acoustic-immittance Characteristics of Children/Silverman and Silman Table 2 Percentage of MEE Sessions with Positive Findings on Zero to Four Acoustic-immittance Measures in the Recurrent* MEE Group (Total vs Normal Hearing) and Percentage of Normal Sessions with Positive Findings on Zero to Four Acoustic Measures in the Control Group Acoustic-immittance Measure Total, Recurrent MEE Group (%) Normal -hearingr Rec urrent MEE G roup (%) Control Gr oup (~) Zero measures One measure S$ TW" TPP IAR** Two measures S+TW S + TPP S + IAR TW + TPP TW + IAR TPP + IAR Three measures S + TW + TPP TW + TPP + IAR S + TPP + IAR S + TW + IAR Four measures (S + TW + TPP + IAR) S = static-acoustic middle-ear admittance ; TW = tympanometric width, TPP = tympanometric peak pressure, IAR = ipsilateral acoustic reflex. "Ears with MEE at four or more sessions during the first year of investigation as determined by microtoscopy and/or pneumotoscopy ; tpta (based on 500, 1000, and 2000 Hz) < 25 db HL ; tstatic less than 0.35 mmho ; "TW greater than 180 dapa ; TPP less than or equal to -100 dapa ; and "*ipsilateral ART greater than 110 db HL or absent. was positive, the positive result was obtained for the TPP or IAR. When two acoustic-immittance measures were positive in this group, nearly all of the positive findings were obtained for the combination involving the TPP and IAR. These findings in the total, recurrent MEE group relating to positive results on just two acoustic-immittance measures cannot be compared with the results of the Utech Smith et al (1993) and Boe et al (1993) studies for the protocol based on a combination of two acousticimmittance measures; Utech Smith et al and Boe et al did not evaluate performance on the remaining two acoustic-immittance measures. This may account for apparent discrepancies in the results for a protocol based on a combination of two acoustic-immittance measures among this investigation, the investigation of Utech Smith et al (1993), and the investigation of Boe et al (1993). Also, there were methodologic differences in the acoustic-reflex activating stimulus (broadband vs tonal) and mode (contralateral vs ipsilateral) between this investigation and that of Utech Smith et al and in the acoustic-reflex activating stimulus level (95 vs 117 db SPL) between this investigation and that of Boe et al. When three measures were positive in the total, recurrent MEE group, the majority of positive findings were obtained for the combination involving the TW TPP, and IAR,. Thus, in general, positive findings on two- or three-measure combinations were most frequently obtained on combinations including the TPP and IAR. In the normal-hearing, recurrent MEE group, during the MEE sessions, negative findings on all or three measures did not occur, similar to the findings for the total, recurrent MEE group. Positive findings on two or more acousticimmittance measures were obtained on 100 percent of the MEE sessions. In the control group, the frequency of positive results (on normal sessions) on none or just one acoustic-immittance measure was 76 percent, as contrasted with 0 to 1 percent for the total, recurrent MEE and normal-hearing, recurrent MEE groups. Moreover, the frequency of occurrence of positive findings on all acousticimmittance measures was strikingly low at 3 percent in the control group. The frequency of positive results on two or more acoustic-immittance measures was only 24 percent in the control group and was much lower than that for the MEE groups. In the control group, when one measure was positive, the IAR or TPP was the measure most frequently affected ; the least frequently

6 Journal of the American Academy of Audiology/Volume 6, Number 4, July 1995 affected measure was the static. When two measures were positive, the static and TW combination was most likely to be affected, in contrast with the TPP and L4R combination for the other MEE groups ; moreover, the TPP and IAR combination was an infrequently occurring twomeasure combination in the control group. When positive findings were obtained on three acousticimmittance measures, they were always obtained for the combination that included the static, TW and TPP Thus, the static and TW tended to be affected frequently in two- and three-measure combinations in the control group. In contrast, in the MEE groups, the static tended not to be affected on two- or three-measure combinations. DISCUSSION n unavoidable limitation of this investiga- A tion was the use of pneumotoscopy/microtoscopy rather than myringotomy as the "gold standard" for diagnosing MEE. The data were collected from children whose parents refused surgery or from the presurgical phase of children who were surgically treated. The findings at the time of myringotomy can confirm a diagnosis made only at the time of the surgery ; the findings cannot confirm a diagnosis made prior to surgery. Therefore, the results at the time of surgery could not have been employed to evaluate the diagnosis at the multiple sessions previous to surgery, at times as early as 3 years prior to surgery. MEE was present at surgery in all of the seven subjects with recurrent MEE who were surgically treated. The results of microtoscopy and/or pneumotoscopy in the subjects with recurrent MEE showed that MEE was present at approximately three out of every four test sessions. Nonetheless, it cannot be concluded, based on this finding, that effusion is present most of the time in the middle ears of children with recurrent MEE as the test sessions occurred, on average, on a trimonthly basis. The findings also revealed that hearing impairment (PTA exceeding 25 db HL) was present in 80 percent of the sessions with MEE in the recurrent MEE group. The results of this investigation substantiated the high sensitivity of the Silman et al (1992) acoustic-immittance protocol and low sensitivity of the ASHA (1990) protocol in the recurrent MEE sample. The sensitivity of the PTA also exceeded the sensitivity of the ASHA (1990) acoustic-immittance protocol based on TW and static. This investigation revealed a marked difference in acoustic-immittance profile between the recurrent MEE group during the otoscopically normal sessions and the control group. For each of the acoustic-immittance measures, especially the TPP and IAR, the false-alarm rate was substantially higher for the recurrent MEE than for the control group. This suggests that even when MEE is absent at a particular session, recurrent episodes of MEE appear to alter the acoustic-immittance characteristics of the middle ear so that they begin to resemble those of children who demonstrate MEE at a given session. This finding may account for differences in false-alarm rates for the acoustic-immittance measures reported by various investigators. That is, some investigators may have included ears from children with recurrent MEE in the control group if the otoscopic findings were normal at a given point in time. Based on the find-' ing of high false-alarm rates of 50 percent or more for the TPP and IAR measures in the recurrent MEE group during the otoscopically normal sessions, perhaps children with recurrent MEE who refuse surgical treatment should be followed until normal findings are obtained on the TPP and/or IAR measures. Research is needed to evaluate this proposal. The acoustic-immittance profile of the total, recurrent MEE group was similar to that for the normal-hearing, recurrent MEE group. Positive results during the MEE sessions on all of the four acoustic-immittance measures occurred in nearly half of the total, recurrent MEE group and in more than one-third of the normal-hearing, recurrent MEE group. Unsurprisingly, positive results on all of the acoustic-immittance measures occurred in only 3 percent of the control group. A positive finding on only one acousticimmittance measure occurred in only 1 percent of the total, recurrent MEE group and 0 percent of the normal-hearing, recurrent MEE group versus 24 percent of the control group. No MEE session in the total, recurrent MEE group or in the normal-hearing, recurrent MEE group had negative results on all of the acoustic-immittance measures. On the other hand, the majority (52%) of the control group had negative results on all of the acoustic-immittance measures. These findings suggest that negative findings on all or three acoustic-immittance measures are consistent with the absence of MEE. Also, positive findings on all acoustic-immittance measures are consistent with the presence of MEE. These findings suggest that audiologists should document the number of positive acoustic- 344

7 Acoustic-immittance Characteristics of Children/Silverman and Silman immittance measures when evaluating children at risk for MEE. The results of this investigation also showed that when positive acoustic-immittance findings were obtained on two of the four acousticimmittance measures in the recurrent MEE group (total or normal hearing), they were obtained overwhelmingly for the TPP and IAR combination and not for other combinations. In the control group, on the other hand, when two of the four acoustic-immittance measures were affected, the TPP and IAR combination infrequently occurred. This suggests that when positive findings are obtained on two of the four acoustic-immittance measures, the pattern should be evaluated ; if the TPP and IAR pattern is present, the child should be considered at risk for MEE. Therefore, children with positive results on two measures - TPP and IAR - should be followed, regardless of the otoscopic status of the middle ear. The findings also revealed that in the recurrent MEE group (total and normal hearing), positive results on the static and/or TW did not occur until three or more of the acoustic-immittance measures were positive. This suggests that pathologic changes in the TW or static occur only after pathologic changes have occurred in the TPP and IAR in subjects with recurrent MEE. Interestingly, positive findings on the static and/or TW did occasionally occur in the control but not recurrent MEE group (total or normal hearing) when one or two measures were positive. These results suggest that positive findings on one measure, especially the static or TW or two-measure static and TW combination, are consistent with the absence of MEE. In conclusion, the findings further corroborate Jerger's (1970) contention that "individually, each measure [acoustic-immittance] has serious limitation. In combination, however, they yield patterns of great diagnosic value" (p. 322). REFERENCES American National Standards Institute. (1991). Maximum Permissible Ambient Noise Leuels for Audiometric Test Rooms (ANSI S ). New York : ANSI. American Speech-Language-Hearing Association. (1990). Guidelines for screening for hearing impairment and middle-ear disorders. ASHA 32(Suppl 2) : Boe RW, Fogarty MJ, Schow RL, Whitaker M. (1993, November). Validity of the ASHA 1990 Hearing Screening Protocol. Poster session presented at the Annual Convention of the American Speech-Language-Hearing Association, Anaheim, CA. Jerger J. (1970). Clinical experience with impedance audiometry. Arch Otolaryngol 92 : Silman S, Silverman CA, Arick DS. (1992). Acousticimmittance screening for detection of middle-ear effusion in children. J Am Acad Audiol 3: Silman S, Silverman CA, Arick DS. (1994). Pure-tone assessment and screening of children with middle-ear effusion. J Am Acad Audiol (in press). Utech Smith PS, Wiley TL, Pyle GM. (1993). Efficacy of ASHA Guidelines for Screening Middle-ear Function in Children. Poster session presented at the Annual Convention of the American Speech-Language-Hearing Association, Anaheim, CA.