Audiology

Internal evaluation of Audiology department, Faculty of Rehabilitation, Tehran University of Medical Sciences, Iran

Mahin Sedaie

Background and Aim: Internal Evaluation means assessment of abilities and potentials. To promote the quality of education, research, health and finally rehabilitation is one of the most important roles and responsibilities of the universities. Promotion of quality of the theoretical and practical education for the Audiology students provides this major with its final goal that is to serve society. The purpose of this study was to evaluate the strength, weaknesses, opportunities and threats (SWOTs) of the Audiology department and to identify the ways of diminishing weaknesses and threats.
Materials and Methods: This descriptive cross-sectional study was conducted on undergraduates, postgraduates, graduates, academic staff, and the director of Audiology department in 9 areas, including management flowchart, educational programs, instructional methods and curriculum models, students, educational areas and equipments, graduate, academic staff, research, and treatment. Data were collected by questionnaires. Results were analyzed descriptively and were expressed in raw and percentage.
Results: The scores of areas in two measures were as follows: management flowchart 4.36 (87.31%), educational programs 4.17 (83.58%), instructional methods and curriculum models 4.01 (80.26%), students 3.43 (68.60%), educational areas and equipment 3.60 (72.11%), from the view of undergraduates, post graduates, faculties, graduates 3.60 (72.03%), academic staff 4.03 (80.6%), research 3.52 (70.4%), and treatment 4.54 (90.80%). The highest score was, therefore, of the treatment area and the lowest belonged to the educational area and equipments. The score of the Audiology department, as the main factor was 3.89 out of 5 which was 77.88%.
Conclusion: Audiology group total score indicates the desirable status that can be promoted to the most desirable if SWOTs are considered.

Fabrication of bioactive glass nanopowder for replacement of ossicles in middle ear

Mohammad Hossein Fathi

Background and Aim: Due to its ability in bonding with hard and soft tissue, healing and repairing of the bone, and proper replacing of the ossicles in middle ear, bioactive glass has come into consideration. The aim of this work was preparation, development and characterization of nanopowder bioactive glass obtained by the sol-gel technique.
Materials and Methods: Bioglass powder was made by sol-gel technique and the presence of desired elements is tested by X-ray fluorescence analysis. Trans Electronic Microscopic (TEM) technique was used to evaluate the powders shape and size. The prepared bioglass powder was immersed in the simulated body fluid solution for 30 days. Fourier transform infrared (FTIR) spectroscopy was utilized to recognize and to confirm the formation of apatite layer on prepared bioglass powder. (XRD) as a structural characterization technique was used to investigate the microstructure.
Results: The glass powder size was less than 100 nanometers. The formation of apatite layer confirmed the bioactivity of the bioglass powder and tests revealed that all the films had the signs of bioactivity. It was also found that at sintering temperatures above 900 ºC, crystalline phase Ca₂SiO₄ was formed.
Conclusion: The sol-gel nanopowder bioglass can be used as a replacement for small bones such as ossicles in middle ear, and it leads to bone osteointegration and growth of the surrounding tissue.

Investigation and comparison of recording time of steady state evoked potentials using three methods of Kalman, Ziarani and adaptive

Dariush Shahbazi-Gahrouei

Background and Aim: Hearing assessment in infants and children younger than two years is an important issue, because the golden time of the language learning and speaking is under the age of two. Steady state auditory evoked potentials (SSAEPs) is one of the best ways of the objective hearing assessment for infants and young children. The need for long time of stimulation and recording restricted the clinical uses of this method. Therefore, the reduction of the recording time is a common problem. SSAEP signals are contaminated with background EEG signals of the brain and nervous system. To discriminate these signals the approach is using averaging method.
Materials and Methods: In this work two adaptive methods were programmed and tried on (SSAEP) signals. The first method was the work of the Ziarani et al. and the second was the enhanced Kalman filter. To assess suggested methods and to compare them with traditional averaging one, two sets of clinical signals prepared with Rotmen research group in university of Toronto were applied.
Results: The speed of the extraction of the SSAEP signals with the Ziarani method is 1.6 times faster than the averaging method. The extraction time of the enhanced adaptive Kalman filter is 13.1 times faster than currently used averaging methods.
Conclusion: The Kalman filter method seems to be more reliable than the other two methods. In addition, this new application of the Kalman filter in hearing assessment could be more beneficial and faster than other methods as an objective method.

Study of denoising in TEOAE signals using an appropriate mother wavelet function

Mohammad Djavad Abolhasani

Background and Aim: Matching a mother wavelet to class of signals can be of interest in signal analysis and denoising based on wavelet multiresolution analysis and decomposition. As transient evoked otoacoustic emissions (TEOAES) are contaminated with noise, the aim of this work was to provide a quantitative approach to the problem of matching a mother wavelet to TEOAE signals by using tuning curves and to use it for analysis and denoising TEOAE signals. Approximated mother wavelet for TEOAE signals was calculated using an algorithm for designing wavelet to match a specified signal.
Materials and Methods: In this paper a tuning curve has used as a template for designing a mother wavelet that has maximum matching to the tuning curve. The mother wavelet matching was performed on tuning curves spectrum magnitude and phase independent of one another. The scaling function was calculated from the matched mother wavelet and by using these functions, lowpass and highpass filters were designed for a filter bank and otoacoustic emissions signal analysis and synthesis. After signal analyzing, denoising was performed by time windowing the signal time-frequency component.
Results: Aanalysis indicated more signal reconstruction improvement in comparison with coiflets mother wavelet and by using the purposed denoising algorithm it is possible to enhance signal to noise ratio up to dB.
Conclusion: The wavelet generated from this algorithm was remarkably similar to the biorthogonal wavelets. Therefore, by matching a biorthogonal wavelet to the tuning curve and using wavelet packet analysis, a high resolution time-frequency analysis for the otoacoustic emission signals is possible.

Cochlear responses and auditory brainstem response functions in adults with auditory neuropathy/ dys-synchrony and individuals with normal hearing

Zahra Jafari

Background and Aim: Physiologic measures of cochlear and auditory nerve function may be of assistance in distinguishing between hearing disorders due primarily to auditory nerve impairment from those due primarily to cochlear hair cells dysfunction. The goal of present study was to measure of cochlear responses (otoacoustic emissions and cochlear microphonics) and auditory brainstem response in some adults with auditory neuropathy/ dys-synchrony and subjects with normal hearing.
Materials and Methods: Patients were 16 adults (32 ears) in age range of 14-30 years with auditory neuropathy/ dys-synchrony and 16 individuals in age range of 16-30 years from both sexes. The results of transient otoacoustic emissions, cochlear microphonics and auditory brainstem response measures were compared in both groups and the effects of age, sex, ear and degree of hearing loss were studied.
Results: The pure-tone average was 48.1 dB HL in auditory neuropathy/dys-synchrony group and the frequency of low tone loss and flat audiograms were higher among other audiogram&aposs shapes. Transient otoacoustic emissions were shown in all auditory neuropathy/dys-synchrony people except two cases and its average was near in both studied groups. The latency and amplitude of the biggest reversed cochlear microphonics response were higher in auditory neuropathy/dys-synchrony patients than control people significantly. The correlation between cochlear microphonics amplitude and degree of hearing loss was not significant, and age had significant effect in some cochlear microphonics measures. Auditory brainstem response had no response in auditory neuropathy/dys-synchrony patients even with low stimuli rates.
Conclusion: In adults with speech understanding worsen than predicted from the degree of hearing loss that suspect to auditory neuropathy/ dys-synchrony, the frequency of low tone loss and flat audiograms are higher. Usually auditory brainstem response is absent in this patients and use of both otoacoustic emissions and cochlear microphonics responses to measure cochlear hair cells function are suggested in them.

A study of the central auditory function in stutters by masking level difference and synthetic sentence identification tests

Nariman Rahbar

Background and Aim: There are evidences that indicate a relationship between auditory processing disorders and stuttering, and any disorder in the central auditory function can be at least one of the underlying causes of stuttering. Even though, using the most state of the art radiographic technologies, i.e. MRI, no definitive answer has been given in relative to this question. In this research, using Mask-ing Level Difference (MLD) and Synthetic Sentence Identification (SSI) tests, the central auditory function of stutters and normal group was evaluated.
Materials and Methods: In this study was analytic cross-sectional, fifteen male patients with stutter-ing and 15 male normal cases with the age range from 16 to 40 years (average age 26.78 year) were evaluated. SSI-ICM, SSI-CCM and MLD tests were performed. The results were compared in both groups.
Results: Although stutterers mean MLD was less than that of normal group, the different was not significant between stutters and normal group in SSI test in right ear at negative MCRs. There was a significant difference in ICM state, but in CCM state, there was no significant difference between the average score of two groups in various MCRs.
Conclusion: The findings of this research is compatible with those of similar researches about the SSI test and the pattern of results, probably indicates a partial dysfunction of brainstem in some of the stutters.

Comparison between phonological priming and semantic in male 18-25 priming in the short verbal memory span

Mohammad Rahim Shahbodaghi

Background and Aim: The short-term memory (STM) has been studied to a great extent so far. Using some strategies and techniques to help the subject to access to his/her memory is important for Speech pathologist. Priming is a process that increases the chance of accessing to some information of memory by means of some simulations. So, primings are some words which facilitate the retrieval of the target words. The purpose of this study is comparing phonological and semantic priming on the short verbal memory span.
Materials and Methods: The research was conducted on sixty-four 18-25 year-old male students in Tehran University of Medical sciences. Due to some distortion factors, including bilingualism, stutter-ing, and articulation problem, that can effect the reaction time, were determined as exclusion critenia. In additiion, subjects with difficulty in Wepman auditory discrimination were ruled out. The test was performed via the second version of programmed DMDX software and reaction time was recorded.
Results: Semantic tasks and rhyming tasks were retrieved faster than the other tasks in lexical access respectively. There was a significant difference between the semantic and rime tasks but there is no significant difference between alliteration and unrelated tasks.
Conclusion: The result of this research indicates that the semantic level is activated faster than the other levels and the phonological level is activated right after that. The alliteration level is the last level that activated. It has some similarities with some other investigations on the reaction time in phono-logical tasks

The comparison study of articulation errors in cochlear implant children before 3 and after 4 years old

Mohsen Saeedmanesh

Background and Aim: Speech is the essential need of the social life. To acquire that, children highly rely on the normal senses and speech full environment. The normal auditory senseis the most important need. Early amplification intervention in children with hearing difficulties is advised. Cochlear implant technology provides an effective help for hearing-impaired children in recent decades. With regards to new and limited implantation services in Iran, the effects of operation age on speech and language of implanted children was not studied yet. The purpose of this study was to compare articulation errors in cochlear implanted children with different operation age.
Materials and methods: In this cross-sectional study, ten cochlear implanted children before three and eleven after four years old were evaluated. The participants were without any anatomical, visual, and intelligence abnormality and 2.5-3 years was passed from their operation. Then, by using Picture Pho-netic Test (PPT), the articulation errors of individuals were extracted and for more evaluation of the er-rors and complete of PPT, we, also used their excited connected speech by presenting pictures. By application of t-test and using SPSS software, the data was analyzed.
Results: Data analysis indicated that, there was meaningful significant difference between substitute errors and whole errors in two gropes but there was not meaningful significant difference between de-stroyed errors in two gropes.
Conclusion: The children who undergoing operation after 4 years old had severed articulation disorder than other grope. These issues indicated that the earlier operation of children will lead to improve the speech skills and reduced the articulation errors.