Biomedical subjects
Publications and source records attributed to R W Keith.
Central auditory disorders in children and adults have become more widely recognized in patients seen by otolaryngologists and audiologists. This article briefly defines those clinical entities, discusses the historic background of testing, and describes current and future test approaches to assessment of central auditory disorders.
The purpose of this paper is to determine the relationship between the SSW and a battery of auditory-language tests in a group of children suspected of auditory processing problems. Thirty-one children between the ages of 6.2 and 10.4 were referred by their classroom teachers. All children were administered a pure tone and an acoustic immittance battery, the SSW test, selected subtests of the Clinical Evaluation of Language Functions, the Goldman-Fristoe-Woodcock Auditory Skills Battery, an elicited language sample, and the Observational Profile of Classroom Communication. No significant correlations were found between the SSW right competing and left competing conditions and the auditory-language test battery. The findings suggest that these two test approaches measure different aspects of auditory processing abilities in children, and both are required to adequately describe auditory processing abilities at all levels.
A review of our experience with evoked potential monitoring of over 100 spinal procedures is summarized here. Typical results of somatosensory cortical evoked potential (SCEP) testing found that latency of responses increased slightly and amplitude decreased substantially from preanesthesia to predistraction with no further changes. SCEP results are effected by many factors, but when they are understood and recognized, evoked potential monitoring can play a significant role in recognizing potential problems and preventing postoperative neurological problems in patients undergoing spinal surgery.
This study was conducted to compare results of SCAN: A Screening Test for Auditory Processing Disorders with other central auditory and language tests. The SCAN, Staggered Spondee Word test (SSW), Competing Sentence test, Peabody Picture Vocabulary Test (PPVT), and the Clinical Evaluation of Language Fundamentals-Revised (CELF-R) were administered to 155 children between the ages of 6 and 15 years. All subjects were referred for possible auditory or language processing disorders. Results showed significant correlations between the SCAN, SSW, and Competing Sentence test results except for Filtered Word and Auditory Figure Ground subtests of SCAN that were not significantly correlated with the Competing Sentence Test. Significant correlations also existed between SCAN and the PPVT, but there were no significant correlations between SCAN and the CELF-R subtests. Patterns of responses according to histories of Attention Deficit Disorders were also found.
Although the protean manifestations of neurofibromatosis have been studied for many years, much is yet to be learned about this disease in young children. Specifically, little is known about the prevalence and significance of early neurotologic abnormalities in this population. Our review of the recent literature, however, failed to identify any publication on the use of ABR and acoustic reflex testing in the pediatric neurofibromatosis population. This study reports on a standardized differential diagnostic battery conducted on 44 children diagnosed as having neurofibromatosis. Results of the neuroaudiologic battery indicated that 32% of the children had significant abnormalities on ABR and acoustic reflex dynamic tests. This is a substantially higher prevalence of abnormalities than reported by another group at a recent NIH concensus meeting on neurofibromatosis. Discussion of the implications of these findings regarding evaluation protocols, as well as management for this select patient population, will follow.
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The purpose of this study was to develop a new multilayer clinical assessment technique to evaluate auditory-language processing abilities in children. Following a 90-min in-service workshop on auditory-language processing problems, 46 nonhandicapped first-, second-, and third-grade students were referred by their classroom teachers for an evaluation of auditory-language processing abilities. Twelve "normally" achieving first-, second-, and third-grade students were randomly selected as controls. Standardized and nonstandardized measures included a pure tone and impedance test, selected subtests of the Clinical Evaluation of Language Functions (Linguistic Concepts, Relationships and Ambiguities, Oral Directions, Spoken Paragraphs, Word Associations, and Model Sentences), the Goldman-Fristoe-Woodcock (GFW) Memory for Sequence Test, Sound Mimicry Test, Sound-Symbol Association Test, and the GFW Test of Auditory Discrimination. Nonstandardized measures included an Observational Profile of Classroom Communication and an informal language sample. Results indicated 87% of 46 (n = 40) children were identified as having auditory-language processing problems. In-service training was an effective means to heighten teachers' awareness for referring subjects. Additionally, the Observational Profile of Classroom Communication was an effective procedure for teachers to systematically observe and document communication behaviors in the context of the classroom.
This study was undertaken to determine the effect of linguistic background on scores obtained by native and non-native subjects on two dichotic speech tests in American English, the staggered spondaic word (SSW) and the dichotic consonant-vowel (CV) tests. Thirty subjects whose native languages were either Hindi or Arabic were tested. Test findings were compared to results obtained from 10 native English-speaking subjects. The non-native English speakers showed abnormally high error scores on the SSW test while the native speakers performed with no errors on that test. Performance on the dichotic CV test was comparable for both the native English and the Hindi subjects, while the Arabic subjects performed significantly worse than the two other groups. These data indicate that tests of speech perception using English must be interpreted with caution when administered to non-native English speakers, and that neither the SSW nor the dichotic CV tests may be assumed to be free of linguistic bias.
Onset latency, rise time, and amplitude measures of the acoustic reflex and auditory brain stem responses (ABRs) to clicks were elicited from normal subjects and subjects with multiple sclerosis (MS). The results indicated that MS subjects exhibited response abnormalities including prolonged rise times of the acoustic reflex and prolonged absolute latencies, interwave latencies and interaural latencies, and poor response stability of the ABR. The results of this study indicate that measurement of acoustic reflex dynamics can add to the diagnostic value of the test beyond measurement of acoustic reflex threshold and decay. The combination of complete acoustic reflex and ABR tests is a valuable contribution to the diagnosis of patients with MS who have no auditory symptoms.
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Clinical usefulness of the neodymium/yttrium aluminum garnet (Nd:YAG) laser in surgery of the middle ear is unproven. An animal study was designed to examine the influence of Nd:YAG laser irradiation on cochlear potentials following vaporization of the stapes. Electrocochleagraphic changes were observed in two of the five animals studied, and caution is advised before using this instrument in humans.
The effect of middle-ear dysfunction and disease on hearing and language development at one year of age was evaluated for 143 high-risk infants. These infants were categorized as normal or abnormal based on otologic history, otoscopic examinations, and on tympanometric examinations. Language was significantly related to gestational age, being delayed by approximately the amount of prematurity. Language scores were therefore adjusted for gestational age. Speech-detection threshold was not related to gestational age, and was used as the measure of hearing. Hearing levels were negatively correlated with adjusted language quotients. Infants with abnormal otologic histories reported were not different from infants with normal histories in either hearing or language development. Infants with bilateral otoscopic abnormalities had significantly higher speech-detection thresholds, but did not differ in language development from those with bilaterally normal otoscopy. Infants who were abnormal bilaterally by tympanometric examination had significantly higher speech-detection thresholds as well as significantly delayed language development. A significant effect on both hearing and language was found among those infants bilaterally abnormal by tympanometry for whom evidence of middle-ear disease was not visualized by otoscopic examination. Implications of these findings are discussed.
In this study, the speech and language skills of children with histories of chronic middle ear effusion were analyzed. Forty-seven children between the ages of one year eleven months and five years five months were given a battery of speech and language tests in the course of a diagnostic evaluation. All the children had been referred to speech pathology by a physician because of a suspected communication disorder. All subjects had histories of three or more episodes of middle era effusion, with the first episode occurring prior to 18 months of age. All medical records were checked and in-depth case histories were obtained in order to rule out other possible complicating factors that might have contributed to a speech and language delay. The results of this study revealed essentially age-appropriate receptive language skills in this group of children. Expressive language and articulatory skills were significantly below chronological age level expectation, indicating the possible serious effects of chronic middle ear effusion on speech and language development.
During exploratory tympanotomy for conductive deafness, the surgeon is occasionally perplexed to find no apparent cause for the air-bone gap. This unexplained deafness has been called "inner ear conductive hearing less" because of the apparent absence of pathology in the middle ear. The incudostapedial joint was studied in 68 vertically sectioned temporal bones and the anatomy is presented. Varying amounts of laxity is observed in the normal joint capsule at the time of surgery. A theory is suggested in which an elongated capsule allows incus motion without energy transmission to the stapes. It is proposed that hypermobility of the incudostapedial joint may exist and explain conductive hearing loss of undetermined etiology.
This paper considers the effect of behavioral responses on stapedial reflex data of neonates. Twenty clinically normal neonates were tested to determine whether repeated acoustic stimulation would habituate the behavioral response, leaving only the stapedial reflex for observation. The results failed to show systematic decline of behavioral response over trials. Stapedial reflex testing indicates a positive response for less than 5% of stimulus presentation. The results are discussed in terms of possible explanation for the apparently low incidence of stapedial reflex in a normal neonatal population.
Three different formulas used in predicting hearing level from acoustic reflex data have been suggested. Acoustic reflex information is also used in predicting slope of hearing loss. Seventy-four normal and hearing-impaired persons were tested, and predictions of level and slope of hearing were compared with pure tone hearing thresholds. The results indicate that the Niemeyer-Sesterhenn and Jerger unweighted formulas yield comparable results and are preferable to the Jerger weighted formula. Predictions of slope of hearing loss are equivocal.
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This study attempted to determine whether word-recognition scores obtained in noise were more sensitive to the presence of a hearing loss than recognition scores obtained in quiet. Subjects with normal hearing, high-frequency cochlear hearing loss, and flat cochlear hearing loss were tested in quiet and in the presence of a 500-Hz low-pass noise. Two signal-to-noise conditions were employed, -4 dB and -12 dB. Words were presented at 40dB SL in one experiment and at 96 dB SPL for normal-hearing subjects in a second experiment. The results indicated that, while the word-recognition scores of groups were similar in quiet, the more negative the signal-to-noise ratio, the greater the separation of group scores, with hearing-impaired subjects having poorer recognition scores than normal-hearing subjects. When the speech and noise were presented at high SPLs, however, the normal-hearing subjects had poorer word recognition than those with flat cochlear losses. The results are interpreted as indicating greater spread of masking in normal-hearing than hearing-impaired subjects at high sound pressure levels.