Judith S. Gravel

“Auditory neuropathy”: physiologic and pathologic evidence calls for more diagnostic specificity

The term auditory neuropathy is being used in a rapidly increasing number of papers in the audiology/otolaryngology literature for a variety of individuals (mostly children) who fulfill the following criteria: (1) understanding of speech worse than predicted from the degree of hearing loss on their behavioral audiograms; (2) recordable otoacoustic emissions and/or cochlear microphonic; together with (3) absent or atypical auditory brain stem responses. Because of the general lack of anatomic foundation for the label auditory neuropathy as currently used, we review the anatomy of the auditory pathway, the definition of neuropathy and its demyelinating, axonal, and mixed variants. We submit that the diagnostic term auditory neuropathy is anatomically inappropriate unless patients have documented evidence for selective involvement of either the spiral ganglion cells or their axons, or of the 8th nerve as a whole. In view of biologic differences between peripheral nerves and white matter tracts in the brain, the term auditory neuropathy is inappropriate for pathologies affecting the central auditory pathway in the brainstem and brain selectively. Published reports of patients with auditory neuropathy indicate that they are extremely heterogeneous in underlying medical diagnosis, age, severity, test results, and that only a small number have undergone the detailed investigations that would enable a more precise diagnosis of the locus of their pathologies. The electrophysiology of peripheral neuropathies and the deficits expected with pathologies affecting the hair cells, spiral ganglion cells and their axons (auditory neuropathy sensu stricto), and brain stem relays are reviewed. In order to serve patients adequately, including potential candidates for cochlear implants, and to increase knowledge of auditory pathologies, we make a plea for more comprehensive evaluation of patients who fulfill the currently used audiologic criteria for auditory neuropathy in an effort to pinpoint the site of their pathologies. We suggest that the term auditory neuropathy be limited to cases in which the locus of pathology is limited to the spiral ganglion cells, their processes, or the 8th nerve, and that the term neural hearing loss be considered for pathologies that affect all higher levels of the auditory pathway, from the brainstem to the auditory cortex.

Auditory consequences of early mild hearing loss associated with otitis media

Two groups of children received periodic documentation of their middle ear status by pneumatic otoscopy in the first year of life and had hearing sensitivity estimated by multiple auditory brainstem response (ABR) assessments during the same period. One group was considered otitis media (OM)-positive, with repeated bilateral episodes of OM and mild conductive hearing loss. The second group was considered OM-free with normal middle ear function bilaterally and normal hearing sensitivity in the first year of life. Childrens higher-order auditory abilities were examined at 4, 6 and 9 years of age. Various measures such as speech recognition-in-competition, visual-auditory learning, sound blending, auditory memory, and masking level difference estimates were utilized to probe the childrens auditory abilities. Results show that children with a first-year history of otitis media demonstrate deficits in the long term in some aspects of higher-order auditory processing. Performance appears to be associated with the mild hearing loss experienced during an important period of early development.

A preliminary account of phonological and morphophonological perception in young children with and without otitis media

This investigation examined the effects of otitis media with effusion (OME) and its associated fluctuating conductive hearing loss on the perception of phonological and morphophonological /s/ and /z/ in young children. We predicted that children free of OME (OME-) would perform better than children with histories of OME (OME+). We also predicted that for the OME+ group morphological perception would be harder than phonological perception, because the former category carries an additional linguistic load (i.e., plurality). Sixteen children, ages 26 to 28 months (M = 26.5, SD = 0.6) were divided into two groups, the OME- (n = 8) and OME+ (n = 8) based on OME history during the first year of life. Subjects in the OME- group were free of the disease for 4/5 visits and pure tone average (PTA) was 12.6 dB HL (SD = 4.8). Subjects in the OME+ group had the disease on 3/5 visits and PTA was 23 dB HL (SD = 2.7). Experimental stimuli were six monosyllabic novel word-pairs. Members of each word-pair differed only in the presence of final voiced or voiceless fricative, marking the targets phonologically (e.g., [g [symbol: see text]]/[g [symbol: see text] s] as in law, loss) or morphophonologically (e.g., [daep]/[daeps] as in map maps). Subjects were taught the unfamiliar word pairs using a fast mapping procedure. Perception was tested with the bimodal preferential looking paradigm. Children in the OME- group performed significantly better than their OME+ counterparts. Individual word-pair analyses showed that OME+ group performed more poorly than the OME- group on one phonological and on two morphological targets, all ending with [s]. For the OME+ group, targets with final [s] posed greater difficulty than those with final [z], especially on morphophonological plural-(s) targets. The results suggested that the fluctuating hearing loss associated with OME might have a negative impact on speech perception.

Early Otitis Media and Phonological Development at Age 2 Years

The effect of early otitis media on phonology and articulation in the presence of expressive language delay was investigated in 16 2‐year‐olds followed prospectively from birth. Eight of the children were designated otitis‐positive and 8 were considered otitis‐negative as determined by bilateral pneumatic otoscopy outcomes during year 1 of life. The groups differed significantly on measures of expressive, not receptive, language development. All members of the otitis‐positive group were expressive language delayed. Phonological analyses were completed on spoken language samples elicited from each child at age 24 months. Results showed similar developmental tendencies in speech sound acquisition between the groups, but the otitis‐positive group had established significantly fewer initial consonant phones and produced them less accurately than the otitis‐negative subject group. The otitis‐positive group acquired significantly fewer consonants with back place of articulation. Similar phonological error patterns of deletion and phoneme class deficiency were used by the groups, but the otitis‐positive group used the error patterns more frequently. Findings here lend support to the otitis media effect as one of interaction among risk factors.

Early Otitis Media, Auditory Abilities, and Educational Risk

Fourteen children whose first-year otitis media (OM) histories were well documented by prospective pneumatic otoscopy were given formal measures of their academic abilities at 6 years of age using ...

Experience with the audiologic assessment of infants and toddlers.

Experience with the behavioral assessment of hearing sensitivity is reported for 211 babies and toddlers aged 6-24 months. The visually reinforced head-turn procedure, visual reinforcement audiometry (VRA), was utilized to obtain threshold estimates for infants evaluated for both research and clinical purposes. At the initial test session, 90% of the infants and toddlers provided useful audiometric threshold data for air-conducted tonal signals; 84% could be assessed using standard earphones. The equipment arrangement described allows a single audiologist to complete the VRA assessment. The behavioral test technique offers the clinician a simple, efficient procedure for the routine audiometric assessment of the vast majority of very young children.

The impact of otitis media with effusion on early phonetic inventories: a longitudinal prospective investigation

This prospective investigation examined the effects of otitis media with effusion (OME) on early speech production. Two groups of infants, the otitis media positive (OME+; n=8), and the otitis media negative (OME-; n=8) were defined according to otitis media (OM) history during the first year of life. OM documentation was based on results from tympanometry, pneumatic otoscopy, and behavioural audiometry collected bimonthly beginning at age 2 months. Phonetic transcriptions were completed from infants recorded babbling samples at 10, 12 and 14 months of age. No differences were found between the two groups on rate of vocalizations (i.e. consonants produced per minute). Differences between the two groups were seen in place and manner of articulation. OME infants produced more bilabial stops than OME- infants who, in turn, produced more alveolar stops and nasals than did their OME+ counterparts. Furthermore, within the OME+ group, children with poorer hearing thresholds showed preference for bilabial stops,...

Long Term Communication Deficiencies in Children with Otitis Media During Their First Year of Life

A cohort of lower socio-economic children who experienced multiple episodes of otitis media (OM) during their first year of life were compared to a group of children who were largely free of OM during their first year. Both groups were followed until 9 years of age. The data indicate that some children with positive histories of OM performed poorer on a variety of communicative tasks across the 9 year age span than the children with the negative histories of OM. The results suggest that the effect of otitis media and its accompanying hearing loss on communication skills may extend throughout childhood.

A Prospective Study of Otitis Media in Infants Born at Very-low Birth weight

Forty-six infants born at very-low birthweight were followed prospectively for a one-year period after their discharge from a neonatal intensive care unit. Pneumatic otoscopy was used to diagnose otitis media at periodic visits to a medical/developmental follow-up program. Twenty-one normal, full-term infants routinely cared for in a well-baby nursery served as control subjects and were followed similarly for the same time period. No difference was found between the two infant groups for the either the percentage of visits infants were considered to have normal middle ears bilaterally or otitis media unilaterally or bilaterally. Further, for the premature infants, no relationship was found between gestational age at birth, birthweight, or length of stay in the intensive care unit and percent-visits with otitis media during the first year.

A Multisite Study to Examine the Efficacy of the Otoacoustic Emission/Automated Auditory Brainstem Response Newborn Hearing Screening ProtocolResults of Visual Reinforcement Audiometry

PURPOSEnThis 3rd of 4 articles on a study of the efficacy of the 2-stage otoacoustic emission/automated auditory brainstem response (OAE/A-ABR) newborn hearing screening protocol describes (a) the behavioral audiometric protocol used to validate hearing status at 8-12 months of age, (b) the hearing status of the sample, and (c) the success of the visual reinforcement audiometry (VRA) protocol across 7 sites.nnnMETHODnA total of 973 infants who failed OAE but passed A-ABR, in one or both ears, during newborn screening were tested with a VRA protocol, supplemented by tympanometry and OAE screening at age 8-12 months.nnnRESULTSnVRA audiograms (1.0, 2.0, and 4.0 kHz) were obtained for 1,184 (82.7%) of the 1,432 study ears. Hearing loss was ruled out in another 100 ears by VRA in combination with OAE, for a total of 88.7% of the study sample. Permanent hearing loss was identified in 30 ears of 21 infants. Sites differed in their success with the VRA protocol.nnnCONCLUSIONSnContinued monitoring of hearing beyond the newborn period is an important component of early detection of hearing loss. Using a structured protocol, VRA is an appropriate test method for most, but not all, infants. A battery of test procedures is often needed to adequately delineate hearing loss in infants. Examiner experience appears to be a factor in successful VRA.