Tehran University Medical Journal

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The main goal of this study is to determine the auditory feedback effects in improvement of speech production process in prelingual totally deaf children who used cochlear implant prosthesis. For this reason, we recorded speech of four prelingual cochlear implant children pre and post of operation. Then we extract some static features of vowels-such as fundamental frequency, formant frequencies, vowel duration and vowel energy-from their stable mid-section and analyze them using a longitudinal prosthesis-on/off analysis. These patients-where are in the range of 7-13 years old-were operated in the cochlear implant clinic of Amiralam hospital. At each session, patients read the sentences once in device-on condition and then after 30 minutes stay in device-off condition. Quantitative results show that at least for the features under study, the patient's reliance on the auditory feedback decreased consistently by time (about 65%-averaged on all three vowels under study and all patients). So we concluded that after a sufficient time of operation, the speech motor patterns of patients will be trained for the correct production of static features of vowels and the relation of patients to auditory feedback for the production of such features considerably decreased by time.

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Histiocytosis under general anesthesia. In these patients, depend on organs involvement and dysfunction, anesthesia technique and specific drugs should be selected.of langerhans cells consist of a range of clinical manifestations, including bone eosimophilic granuloma, Hand-Schuller-Chiristian syndrome and Letterer-Siwe disease. Definitive diagnosis is based on biopsy of involved tissues. This report describes anesthesia technique in a 2 years old girl for diagnostic biopsy

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Background: The objective of this study was to describe the audiologic and related characteristics of a group patient with speech perception affected out of proportion to pure tone hearing loss. A case series of patient were referred for evaluation and management to the Hearing Research Center.To describe the clinical picture of the patients with the key clinical feature of hearing loss for pure tones and reduction in speech discrimination out of proportion to the pure tone loss, having some of the criteria of auditory neuropathy (i.e. normal otoacoustic emissions, OAE, and abnormal auditory brainstem evoked potentials, ABR) and lacking others (e.g. present auditory reflexes).
 Methods: Hearing abilities were measured by Pure Tone Audiometry (PTA) and Speech Discrimination Scores (SDS)), measured in all patients using a standardized list of 25 monosyllabic Farsi words at MCL in quiet. Auditory pathway integrity was measured by using Auditory Brainstem Response (ABR) and Otoacoustic Emission (OAE) and anatomical lesions Computed Tomography Scan (CT) and Magnetic Resonance Image (MRI) of brain and retrocochlea. Patient included in the series were 35 patients who have SDS disproportionably low with regard to PTA, absent ABR waves and normal OAE.
Results: All patients reported the beginning of their problem around adolescence. Neither of them had anatomical lesion in imaging studies and neither of them had any finding suggestive of conductive hearing lesion. Although in most of the cases the hearing loss had been more apparent in the lower frequencies (i.e. 1000 Hz and less), a stronger correlation was found between SDS and hearing threshold at higher frequencies. These patients may not benefit from hearing aids, as the outer hair cells are functional and amplification doesn’t seem to help though, it was tried for all.
Conclusion: These patients share a pattern of sensory –neural loss with no detectable lesion. The age of onset and the gradual deterioration are remarkable. It seems that this is a new category of sensory –neural haring loss which deserves more attention.