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Biomedical subjects

Jane A Baran

Publications and source records attributed to Jane A Baran.

6 recordsLinked to original sources

GIN (Gaps-In-Noise) test performance in subjects with confirmed central auditory nervous system involvement.

OBJECTIVE: The purpose of the present study was to investigate the value of a new gap detection procedure called Gaps-In-Noise (GIN) for assessment of temporal resolution in a clinical population. DESIGN: The test consists of 0 to 3 silent intervals ranging from 2 to 20 msec embedded in 6-sec segments of white noise. The location, number, and duration of the gaps per noise segment vary throughout the test for a total of 60 gaps presented in each of four lists. The GIN procedure was administered to 50 normal-hearing listeners (group I) and 18 subjects with confirmed neurological involvement of the central auditory nervous system (group II). RESULTS: Results showed mean approximated gap detection thresholds of 4.8 msec for the left ear and 4.9 msec for the right ear for group I. In comparison, results for group II demonstrated a statistically significant increase in gap detection thresholds, with approximated thresholds of 7.8 msec and 8.5 msec being noted for the left and right ears, respectively. Significant mean differences were also observed in the overall performance scores (i.e., the identification of the presence of the gaps within the noise segments) of the two groups of subjects. Finally, psychometric functions, although similar for short and long duration gaps, were highly different for gaps in the 4- to 10-msec range for the two groups. CONCLUSIONS: A variety of psychoacoustic procedures are available to assess temporal resolution; however, the clinical use of these procedures is minimal at best. Results of the present study show that the GIN test holds promise as a clinically useful tool in the assessment of temporal resolution in the clinical arena.

Adolescent↗

Differential attention effects on dichotic listening.

The role of attention in the differentiation of auditory processing disorders from attention deficit disorders is gaining considerable interest in both the clinical and research arenas. It has been well established that when attention is directed to one ear or the other on traditional dichotic tests, performance can be altered. However, preliminary studies in our laboratory have shown that dichotic fusion paradigms are resistant to shifts in ear performance associated with changes in attention. The purpose of this study was to assess the performance of normal listeners on a dichotic consonant-vowel and a dichotic rhyme (fusion) test. Both test procedures were administered to 20 young adults in three different listening conditions (free recall, attention directed to the left ear, and attention directed to the right ear). Results from this study supported the hypothesis that dichotic rhyme tests are resistant to alterations in the laterality of attention and have implications for the development of test paradigms that can be used to segregate attention from pure auditory deficits in the clinical domain.

Acoustic Stimulation↗

Central auditory deficits associated with compromise of the primary auditory cortex.

The subject of this study was a 46-year-old female who had suffered a cerebrovascular accident (CVA). Magnetic resonance imaging revealed damage in the area of the distribution of the middle cerebral artery involving most, if not all, of the primary auditory area of the left hemisphere. No auditory problems were noted prior to the CVA; however, following the CVA, the subject reported a number of auditory difficulties. Pure-tone thresholds were normal post-CVA, and performance on speech recognition testing was good in both ears if ample time was provided between a response and the presentation of the next test item. Duration pattern, intensity discrimination, and middle latency response test results were abnormal for both ears, and right ear deficits were evident on an auditory fusion test and two dichotic speech tests (digits and rhymes). This case is significant in that it demonstrates a good correlation between damage to known key auditory regions and central auditory test results.

Audiometry, Pure-Tone↗

Assessment and remediation of an auditory processing disorder associated with head trauma.

This case study involves a 41-year-old female who had sustained a mild traumatic brain injury during a horseback riding accident. The patient was seen for medical and neuropsychological testing following this incident and was referred to a speech-language pathologist for rehabilitative services. At 13 months posttrauma, the patient, who was frustrated by a lack of significant progress, requested an audiologic work-up. Results of testing conducted at this time revealed normal peripheral hearing and significant central auditory deficits. Based on these findings, an auditory rehabilitation program was developed and implemented. The components of this patient's rehabilitation program are reviewed, and the posttherapy improvements noted in her auditory functions are detailed. The case is important in that it demonstrates (1) that auditory deficits can be a sequel to minor head injury, (2) that these deficits are often subtle and may not be detected unless central auditory testing is conducted, and (3) that these deficits may be amenable to remediation.

Adult↗

Central deafness associated with a midbrain lesion.

Central deafness has been linked historically to bihemispheric involvement of the temporal lobe, with more recent findings suggesting that compromise of other cortical and subcortical structures can also result in this disorder. The present investigation extends our understanding of the potential anatomical correlates to central deafness by demonstrating that bilateral involvement of an auditory structure within the midbrain can additionally result in this condition. Our subject was a 21-year-old male with a subarachnoid bleed affecting both inferior colliculi. Significant auditory deficits were noted for the middle and late auditory evoked potentials, while electrophysiologic measures of the periphery indicated normal function. The patient was enrolled in a rehabilitation program for approximately 14 weeks. Although initially unresponsive to sounds, the patient regained most of his auditory abilities during the 10 months he was followed. This case documents the range of auditory deficits that may be associated with damage to the inferior colliculi, and it profiles a hierarchical recovery of auditory function consistent with test findings.

Adult↗

Audiological correlates to a rupture of a pontine arteriovenous malformation.

This is a report of a female patient in her midthirties who sustained a hemorrhage secondary to an arteriovenous malformation in the region of the pons. The patient's initial symptoms included hearing loss and tinnitus, which were followed by the more characteristic symptoms of headache and loss of consciousness. Results of audiological testing at three months postaccident documented the presence of a hearing loss and a central auditory processing disorder, and the patient was provided an auditory rehabilitation program. Follow-up testing over the course of an additional year documented improvement in both pure-tone threshold and central test results; however, at 15 months postaccident, some auditory deficits remained, especially in the ear ipsilateral to the primary site of lesion. The anatomical correlates of these deficits are discussed, as are the potential contributions of both the auditory rehabilitation program and spontaneous recovery mechanisms to the documented improvements in auditory function.

Adult↗