Identification Of Conductive Hearing Loss In Young Infants PDF

Identification of Conductive Hearing Loss in Young Infants Using Tympanometry and Wideband Reflectance Beth A. Prieve,1 Kathy R. Vander Werff,1 Jonathan L. Preston,2 and Lea Georgantas3 Objective: The goal of the study was to evaluate the effectiveness of diagnosis of he...

Identification of Conductive Hearing Loss in Young Infants Using Tympanometry and Wideband Reflectance Beth A. Prieve,1 Kathy R. Vander Werff,1 Jonathan L. Preston,2 and Lea Georgantas3 Objective: The goal of the study was to evaluate the effectiveness of diagnosis of hearing loss and used in combination with air- and tympanometry and wideband reflectance (WBR) in detecting conductive bone-conducted thresholds to provide critical information that hearing loss (CHL) in young infants. aids in the diagnosis of conductive hearing loss (CHL). CHL is Methods: Type of hearing loss was determined using auditory brain- traditionally defined as the difference (in decibels) between air stem response using air- and bone-conducted tone bursts in 84 ears and bone conduction pure-tone behavioral thresholds. CHL is from 70 infants (median age = 10 weeks). Of these 84 ears, 60 are also measured in infants using the auditory brainstem response included in the current analysis: 43 with normal hearing (NH) and 17 (ABR) evoked by tone bursts (Vander Werff et al. 2009) and with CHL. Tympanometry was measured using probe tone frequencies auditory steady state responses (Small & Stapells 2008). For of 226, 678, and 1000 Hz. Tympanograms were evaluated in two ways: audiologists, it is critical to define middle ear measures that (1) Acoustic middle ear admittance (Ya, in millimhos); and (2) two-cate- accurately distinguish ears with and without CHL. gory classification (normal/abnormal), as described by Baldwin (2006). Two measures used currently to clinically evaluate middle Measures of Ya were evaluated in two ways: by admittance-magnitude tympanograms and calculated admittance magnitude from subcompo- ear function are tympanometry and wideband acoustic transfer nents (conductance and susceptance). WBR was measured in response functions (WATF). Tympanometry provides a measurement to a chirp stimulus after probe calibration. WBR was analyzed into thir- of acoustic middle ear admittance (Ya). Negative and positive teen 1/3 octave bands. Tests for statistical differences for two-category pressures are applied to the ear canal in the presence of a probe classification were analyzed using Chi-squared and Ya, and WBR were tone to separate Ya from that of the air trapped between the analyzed using repeated-measures analyses of variances. Cohen’s d and probe and the eardrum (Yec). Tympanometry has been part of likelihood ratios were computed for comparison with statistically signifi- the test battery for decades in older children and adults using cant differences. a 226 Hz probe tone. Because early case studies indicated that Results: Ya measured with 678- and 1000 Hz probe tones was signifi- tympanometry using a 226 Hz probe tone did not identify middle cantly different between ears with CHL and NH. Two-category classifi- ear effusion in infants less than 7 months of age (e.g., Paradise et cation of tympanograms using a 1000 Hz probe tone was significantly al. 1976), higher-frequency probe tones have been recommended. different between ears with CHL and NH. Neither two-category classifica- Descriptive characteristics of middle ear function using a 1,000 tion nor Ya was significantly different between ears identified with CHL Hz probe tone have been published for newborn ears screened in and NH using a 226 Hz probe tone. WBR was significantly higher in the the neonatal intensive care unit (Sutton et al. 1996; Margolis et frequency bands 800 to 2500 Hz and in the frequency band centered at al. 2003; Alaerts et al. 2007; Shahnaz 2008), well-baby nursery 6300 Hz in infants with CHL. Effect sizes (Cohen’s d) were greater than 2 (McKinley et al. 1997; Kei et al. 2003; Margolis et al. 2003; for several WBR frequency bands and Ya measured with 1000 Hz probe tones. The results were similar for calculations of Ya from admittance- Alaerts et al. 2007; Mazlan et al. 2007; Shahnaz et al. 2008; magnitude and subcomponent tympanograms. Positive likelihood ratios Sanford et al. 2009; Hunter et al. 2010), and for infants between for WBR ranged between 8.1 and 38, and those for Ya using 1000 Hz 1 and 4 months of age, who have otoacoustic emissions (OAEs) ranged between 12.5 and 32. (Alaerts et al. 2007; Lyra e Silva et al. 2007; Mazlan et al. 2007). Ya is lower in infants who failed newborn hearing screening than Conclusions: CHL in young infants can be detected well with WBR or for those who passed, suggesting that failed newborn hearing tympanometry using probe frequencies of 678 and 1000 Hz. screening was due to outer or middle ear blockage (Sanford et al. (Ear & Hearing 2013;34;168–178) 2009; Hunter et al. 2010). It has also been shown that Ya is low for infants judged to have effusion by imaging (Zhiqi et al. 2010) or INTRODUCTION abnormal eardrum appearance judged through otoscopy (Garcia et al. 2009). Although these experiments indicate a statistical The Joint Committee on Infant Hearing (JCIH, 2007) out- relationship between low Ya and failed newborn hearing screening lines recommendations for early hearing detection and interven- or middle ear effusion, the studies do not test the clinical utility of tion (EHDI) programs that include universal newborn hearing Ya in detecting CHL in infants. screening by 1 month of age, audiological and medical diagno- The accuracy of identifying CHL in infants with tympa- sis of hearing loss by 3 months of age, hearing aid fitting within nometry has not been extensively examined. Although stud- 1 month of diagnosis of hearing loss, and enrollment in an early ies exist for older children (Piskorski et al.1999), few studies intervention program by 6 months of age. Measurement of exist for infants. Baldwin (2006) studied tympanometry in 104 middle ear function is recommended as part of the audiological infants who had no evidence of CHL (present ABR to click stimuli 10 is interpreted as large and < 0.001; partial η2 = 0.366) and group (F = 60.0; p < 0.001; almost-conclusive increase of the likelihood of the condition, partial η2 = 0.496). There was also a significant interaction whereas an LR+ of 1 indicates no change in the likelihood between frequency band and group (F = 13.7; p < 0.0005; of the disorder. LR+ between 1 and 10 indicates small to partial η2 = 0.191), indicating that the pattern of WBR across moderate increases in the likelihood of the condition/disease. frequency bands was different for the two groups. Because LR− indicates the decreased likelihood that an individual ear of the interaction, post hoc testing was performed between has the condition/disease. An LR–