ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The gain of a hearing aid was measured on each of eight subjects using a variety of functional (subjective) and insertion (objective) gain methods. Each measurement was repeated on subsequent days and the hearing aid gain was also determined in several couplers and on KEMAR. The multiple measurements enabled an accurate estimate of the “true” gain of the aid on each subject to be determined. The real ear gain measured by each of the individual methods was then compared with this true gain estimate and the relative accuracy of each method was quantified. Of the clinically feasible methods, probe microphone measurement of insertion gain proved to be the most accurate. Few significant differences were found between functional gain and insertion gain. Estimation of real ear gain on the basis of coupler gain appeared to be a reasonable, though not recommended approach.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Congenital and early-onset hearing losses were discovered in 6.1% of 975 Intensive Care Nursery (ICN) graduates. The methods used were neonatal screening by Crib-0-Gram (COG) and high risk register, in combination with repeated behavioral hearing tests at 1 to 3 years. This 7-year longitudinal study had follow-up hearing evaluations for a remarkably high 84% of all subjects. Significant losses that interfered with speech and language development (1000 to 8000 Hz average loss >45 dB HL bilaterally) were found in 4.3% of infants. COG in combination with subsequent behavioral hearing screening was a sensitive strategy for detecting significant hearing loss: only one child was missed with this combination. Alone, COG sensitivity to significant hearing losses was 79.3%, but would have been higher had a stricter passing criterion been adopted. Behavioral hearing screenings detected bilateral hearing losses of even mild (>20 dB HL) degree. Sensitivity to significant hearing losses was 82.6% and would have been improved if test frequencies >3000 Hz were included in the screen. Even if screening failure occurred at 1 year of age, the age of actual confirmation of hearing loss depended on severity of the loss and ear involvement. Significant hearing losses were confirmed earlier than less severe or unilateral losses. Although behavioral screenings could be done during the first year of life, continued follow-up was required to detect progressive hearing losses.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Two simple overall measures of health—length of stay in the Intensive Care Nursery (ICN) and gestational age-predict hearing loss in ICN graduates. Craniofacial anomalies, congenital perinatal infections, and meconium aspiration are strong predictors of hearing loss, especially in term infants. Findings are based on univariate and multivariate analyses of a number of variables that might be associated with permanent hearing loss. Study variables included all seven High Risk Register items and a number of other features of the ICN history. They were examined in 799 ICN graduates whose hearing had been monitored in their first few years of life. These babies composed 40% of the ICN population and were selected because they had one or more “high risk” factors in their neonatal history. Prevalence of hearing loss in this high risk sample was similar to that found in other ICN samples. Prevalence of hearing loss associated with individual Risk Register items was similar to other published findings for some items and not for others.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Prospective screening of an extremely high risk group of 137 infants cared for in the Newborn Intensive Care Unit of the James Whitcomb Riley Hospital for Children was undertaken during 1983. Auditory brain stem responses (ABR) were obtained utilizing a clinical evoked potential system (Madsen 2250). Patients were selected for screening prior to discharge or transfer to the referring hospital on the basis of one or more of the following criteria: birth weight <1250 grams; birth weight <1500 grams and ventilatory support; significant depression at birth (Apgars <3 and 6 at 1 and 5 minutes, respectively); seizures, meningitis, and/or sepsis. Of the original 137 infants tested, 82 passed the initial ABR, 22 conditionally passed, and 34 failed. Eighty-two infants had follow-up behavioral and audiometric testing while 20 infants died and 35 were lost to follow-up. Four infants had severe sensorineural hearing loss, each of whom had failed the initial ABR. None of the infants who initially passed or conditionally passed the ABR had sensorineural hearing loss on followup testing. High risk factors for sensorineural hearing loss in the neonatal period included: intraventricular/periventricular hemorrhage, apnea, family history, major malformations of the head and neck, and possibly hyperbilirubinemia and congenital infection. No relationship of sensorineural hearing loss with very low birth weight, hyponatremia, infection, seizures, or medications was found. On the basis of these data, it is suggested that electrophysiologic hearing screening of a high risk population may be delayed until 3 to 6 months of age to improve specificity of testing.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The connected discourse tracking procedure was adopted for use as a production training task for profoundly hearing-impaired children. A clinician served as the receiver and 5 children with profound hearing losses each served as the sender for 16 tracking sessions. There were individual differences among the children in their ability to convey the connected discourse to the clinician over time. The increase in comprehension of each subject's speech during the last session relative to the amount of information understood during the first session ranged from 0 to 48%. Two independent observers were used during the first and last sessions to verify the tracking results obtained by the clinician (the primary receiver). There were differences in words tracked per minute among the three receivers with the primary clinician achieving higher tracking rates than the other two. The children learned how to use discourse strategies when they were not understood and they were highly motivated by the task. The results indicate that it is feasible to incorporate the procedure in speech training program for hearing-impaired children.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Relationships among a number of pre- and postimplant variables measured in 20 adults implanted with a single-channel cochlear implant were examined through a variety of univariate and multivariate statistical techniques. A large number of variables were analyzed to yield information on the relationships between pre and postimplant performance, and among a variety of postimplant measures. Variables included: age; etiology and nature of deafness; type of implant worn; pre- and postimplant warble tone and speech detection thresholds; postimplant performance on the Monosyllable-Trochee-Spondee (MTS) and Environmental Sounds tests; postimplant electrical thresholds, uncomfortable loudness levels, and dynamic range; I.Q. scores; and postimplant discourse tracking performance with and without the implant. The difference score on the discourse tracking task, representing the auditory advantage over performance with lipreading alone, related substantively to a combination of variables including type of unit worn (Sigma versus Alpha), nature of deafness (progressive versus sudden), and etiology (meningitis versus nonmeningitis). Additionally, MTS and Environmental Sounds test scores were found to relate to one another and to etiology and nature of deafness.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Errors on a nonsense syllable test (NST) were compared to pure-tone thresholds and ages of 109 subjects with normal or sensorineural hearing loss. A strong correlation was found between the number of NST errors and hearing loss at 2000 and 250 Hz. NST errors do not appear to be related to the age of subjects. Excellent predictive relationships were found between total NST errors and a weighted pure-tone average for slight to marked sensorineural hearing loss. Implications for counseling, site of lesion, and amplification evaluation are discussed.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Evidence reported in the literature indicates that wave I of the auditory brain stem response is influenced by cochlear contributions from a more basal area of the cochlea than is wave V. This phenomenon is invoked to explain different latency-intensity function patterns of waves I and V and the I-V interval for four types of cochlear hearing loss. In high frequency hearing losses wave V is delayed at low intensities. Wave I tends to be delayed at all intensities and by a greater amount than wave V. The I-V interval is often reduced with the effect maximal at higher intensities. Low frequency hearing losses tend to cause early wave latencies at low intensities. Wave I latencies are normal. The V interval is therefore reduced at lower intensities. Flat hearing losses produce normal latency-intensity functions. High frequency notched audiograms are almost always associated with delayed wave V but early wave I latencies. The I-V interval is therefore significantly prolonged with the effect maximal at low intensities. The variability of the I-V interval as a function of audiometric configuration indicates that it is not a pure measure of central conduction time.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

This note proposes that a statistical index, the standard error of the mean, be used in determining a posteriori whether an adequate subject sample has been selected for auditory brain stem response laboratory norms. When the standard error calculated is within the laboratory's resolution of measurement, the data set obtained provides a good estimate of the true population mean, obviating the need for sampling additional subjects.

ISSN:0196-0202    

出版商:OVID    

年代:1987

数据来源: OVID