Auditory and Vestibular Research
Volume:16 Issue: 2, 2008

Assessment of central auditory processing skills needs various behavioral tests in format of a test battery. There is a few Persian speech tests for documenting central auditory processing disorders. The purpose of this study was developing a dichotic test formed of one-syllabic words suitable for evaluation of central auditory processing in Persian language children and reporting its preliminary results in a group of normal children.

Persian words in competing manner test was developed utilizing most frequent monosyllabic words in children storybooks reported in the previous researches. The test was performed at MCL on forty-five normal children (39 right-handed and 6 left-handed) aged 5-11 years. The children did not show any obvious problem in hearing, speech, language and learning. Free (n=28) and directed listening (n=17) tasks were investigated.

The results show that in directed listening task, there is significant advantage for performance of pre-cued ear relative to opposite side. Right ear advantage is evident in free recall condition. Average performance of the children in directed recall is significantly better than free recall. Average row score of the test increases with the children age.

Persian words in competing manner test as a dichotic test, can show major characteristics of dichotic listening and effect of maturation of central auditory system on it in normal children.

Vestibular evoked myogenic potential (VEMPs) is one of the clinical tools to evaluate vestibular function. The VEMPs can be recorded from sternocleidomastoid muscle by auditory stimulation with various sound stimuli and are thought to have saccular origin. The aim of this study was to compare the VEMP responses evoked by short (500 Hz) tone burst (STB) with those evoked by click stimuli in healthy young individuals.

Thirty healthy volunteers (15 males, 15 females) with ages of 18 to 30 years were enrolled in this study. Subjects were instructed to sit on a chair and rotate their head to the opposite side of the recording muscle. The VEMPs was recorded using 500 Hz STB and then click sound stimuli to each ear. The p13 and n23 latencies, p13-n23 peak-to-peak amplitude and VEMPs thresholds were obtained for further analysis.

The VEMP responses were present in all subjects for STB and ware not recorded in one subject for click. The latencies of p13 and n23 of STB-VEMP were significantly longer, and the p13-n23 amplitudes were significantly greater for STB-VEMP (p<0.05), and thresholds were higher for clicks (p < 0.05). No significant difference was obtained between both ears and genders. (p > 0.05).

The VEMP responses were significantly different between the stimuli of STB and click, and the norms of different stimuli should be established for clinical interpretations. According to these data, we recommend STB stimuli in comparison with clicks for clinical diagnosis.

One of the most important problems of children who suffer from autism is abnormality in receiving and integrating sensory inputs, especially hearing input. It has been shown that brainstem has a key role in receiving, encoding and integrating hearing input. Auditory brainstem response (ABR) is a tool by which we can evaluate this function. The purpose of this study was to assess and to compare autistic and normal children brainstem hearing function.

This case-control study was conducted on thirty (58 ears) autistic and thirty (57 ears) normal 6-12 years old children. The children with autism were divided into slight and severe subgroups according to Autism Diagnostic Interview-Revised questionnaire. Click-evoked ABR was recorded and compared between groups.

There was significant difference between two groups V and III wave latencies and I-III and I-V interpeak latencies (p<0.05). In fact, comparison of the results of autism subgroups with normal children indicated that the latencies of the severe subgroup significantly prolonged.

Increasing latencies of ABR waves in severe subgroup maybe due to abnormality in low level of brainstem. Brainstem abnormality may result in exacerbating the symptom of autism. It is therefore suggested that ABR is included in diagnostic test batteries for these patients.

Middle latency auditory evoked potentials (MLAEPs) development takes longer time than the auditory brainstem response (ABR) development does, which makes them difficult to record in some children. The purpose of this study was to investigate the age effect on characteristics and detection of MLAEPs in children and adults.

This cross sectional study was conducted on 15 children aged 7-12 yr and 31 adults aged 20-50 yr with normal peripheral hearing. To investigate precisely, children were divided in two subgroups of older and younger than 10 years old, as well. The MLAEPs amplitudes and latencies were recorded by conventional protocol and compared.

Adult Na mean latency, 20.86 ms, was less than that of children, 22.86 ms, (p=0.0025). In contrast, the adult Nb mean latency, 44.93 ms, was longer (p=0.0001). Children Nb mean latency was 42.02 ms. There was no significant difference in MLAEP amplitudes and latencies between two children subgroups, although variance was more in younger children.

MLAEPs are reliably recorded after 7 years old. Characteristics of MLAEPs are different in adults and children so that the primary MLAEPs generators have a course of development extending beyond the first decade of life. As those potentials were recorded in all children, it is suggested to be used in their test batteries for hearing evaluation.

Hyperbilirubinemia during the neonatal period is known to be an important risk factor for neonatal auditory impairment, and may reveal as a permanent brain damage, if no proper therapeutic intervention is considered. In the present study some electroacoustic and electrophysiologic tests were used to evaluate function of auditory system in a group of children with severe neonatal Jaundice. Forty five children with mean age of 16.1 14.81 months and 17 mg/dl and higher bilirubin level were studied, and the transient evoked otoacoustic emission, acoustic reflex, auditory brainstem response and auditory steady-state response tests were performed for them. The mean score of bilirubin was 29.37 8.95 mg/dl. It was lower than 20 mg/dl in 22.2%, between 20-30 mg/dl in 24.4% and more than 30 mg/dl in 48.0% of children. No therapeutic intervention in 26.7%, phototherapy in 44.4%, and blood exchange in 28.9% of children were reported. 48.9% hypoxia and 26.6% preterm birth history was shown too. TEOAEs was recordable in 71.1% of cases. The normal result in acoustic reflex, ABR and ASSR tests was shown just in 11.1% of cases. The clinical symptoms of auditory neuropathy were revealed in 57.7% of children. Conducting auditory tests sensitive to hyperbilirubinemia place of injury is necessary to inform from functional effect and severity of disorder. Because the auditory neuropathy/ dys-synchrony is common in neonates with hyperbilirubinemic, the OAEs and ABR are the minimum essential tests to identify this disorder.

Hearing loss is one of the most prevalent chronic conditions affecting the elderly. The impacts of hearing loss are depression, social isolation, and functional disability, particularly for those who have not yet been evaluated or treated for hearing loss. The aim of this study was audiologic screening and assessing candidacy for hearing aid in the elderly people. This analytic-cross sectional study was performed on 52 older adults aged from 51 to 97. Subjects were evaluated according to ASHA guidelines for audiologic screening in adults (1997). Using HHIE-S as hearing disability screening instrument, the need for hearing aid use was evaluated. About 86 percent of subjects had some degree of hearing loss. There were significant correlation between PTA(0.5, 1, 2) KHz>26 and HHIE-S>10. According to these two factors 21.2 percent of subjects needed to use hearing aid while 18 percent of this group had hearing aids. There is high prevalence of hearing loss among older adults, thus it's necessary to evaluate the need for hearing aid in this rapidly growing population. Among different factors affecting hearing aid candidacy the most correlated were PTA(0.5, 1, 2)KHz>26 and HHIE-S>10. Therefore according to this study by combination of these two evaluation of hearing aid candidacy would be more appropriate.

Objective measurement is general and acoustic measurements in particular have become a substantial aspect of stuttering assessment during the last few decades. Measurements do not replace the perceptual judgment, but they allow a more precise diagnosis, provide more evidence for therapeutic interventions, and are useful as feedback for patients in therapy. The purpose of this investigation was to compare some adult male stutterer's and nonstutterer's acoustic features. Adult male stutterers and nonstutterers participated this case-control study. Their fluent reading of 20 sentences in Farsi, prolongation of vowels /a/ and /i/, and rhythmic counting from 1 to 20 were analyed with Dr. Speech software. There were no significant differences between two groups in fundamental frequency (f0) and standard deviation of f0 in three speech samples (vowels /a/ and /i/, reading 20 sentences, and rhythmic counting from 1 to 20). No significant difference were between two groups for jitter and shimmer. Non significant differences between two groups are somewhat due to investigation of this parameters in fluent speech of stutterers and nonstutterers.

Fluent aphasia and Alzheimer patients have difficulties in perception and naming. Patient with fluent Aphasia and Alzheimer disease, both have difficulty in perception and naming. Their site of lesion is also identical, that is temporoparietal lobe which is damaged in both group. This study investigates the effects of semantic and phonological cues in facilitation of word finding. The study was prescriptive - analytic cross-sectional with 14 patients. The participants were seven fluent aphasia with mean age 48.4 year old and seven Alzheimer patients with mean age 69/71 year old and mean Mini-Mental State Examination (MMSE) 16 score. Those were assessed with Persian Naming Test. The Aphasic patients were selected from Tehran University hospitals and Alzheimer ones were from Rouzbeh hospital and Alzheimer Association of Iran. Mean semantic and phonological cues in fluent aphasia patients were 2.71 and 12.29, respectively, which significantly different (p=0.01), but those results were 8.29 and 3.43 in Alzheimer patients, that were not significantly different (p>0.05). A main result of this study was significant difference between two cues in both groups. Two groups of patients use two cues in word finding. The correct responses increase with phonological cue in fluent aphasia but semantic cue has the main role for naming in Alzheimer patients.