Hearing aid selection as the first step in modifying the hearing loss is a critical point . people with severe to profound hearing loss need special consideration. In order to determine the amount of gain and output of hearing aids, some formulae are presented. Although most of these formulae are planned for mild to moderate hearing loss, they are used for severe to profound hearing losses. POGO method is one of these formulae.This method, based on halving the hearing threshold, is not suitable for profound hearing loss. There are some considerations in revising this method for severe to profound hearing loss and it’s name has changed to POGO II, too.

People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss . In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter,  stimulator and receiver, and electrode array.

 People with profound hearing loss are not able to use some kinds of conventional amplifiers due to the nature of their loss. In these people, hearing sense is stimulated only when the auditory nerve is activated via electrical stimulation. This stimulation is possible through cochlear implant. In fact, for the deaf people who have good mental health and can not use surgical and medical treatment and also can not benefit from air and bone conduction hearing aids, this device is used if they have normal central auditory system. The basic parts of the device included: Microphone, speech processor, transmitter,  stimulator and receiver, and electrode array.

The disastrous effects of Hearing loss on speech and language development can be minimized by early interventions. Profoundly deaf or hard of hearing children not benefitting enough from other kinds of hearing aids are referred for surgically implanted electronic cochlear implant that provides a sense of sound or comprehension of speech. Evaluation and management of pediatric patients is performed by cochlear implant team which consists of different specialists and doctors. Selecting children for the implant surgery is performed based on the certain criteria suggested by Staller et. al. in 1991. All the patients undergo comprehensive medical and Audiological evaluations before the surgery.In this article we will review different process of cochlear implant surgery and pre- surgery Audio logical evaluations in brief.

Background and objectives: This article is aimed at: 1.studying the relationship between Bone conduction pure tone thresholds and speech reception thresholds via bone conduction in normal patients 2.studying the stability and repeatability of the speech reception thresholds via bone conduction and 3. Comparing the characteristics of the function of the speech gain via bone conduction with that of air conduction.
Method: 60 normal hearing subjects (30 males and 30 females) were evaluated by air conduction pure tone audiometry, bone conduction pure tone audiometry and speech reception thresholds.
Results: Findings for the mentioned tests in all subjects were statistically insignificant. The results are prepared in tables and charts.
Conclusion: Pure tone thresholds and speech reception thresholds acquired by means of air conduction testing and bone conduction testing and the stability and repeatability were similar in both evaluations.

Method and Materials: This cross - sectional survey is carried out in pediatric clinic department of audiology faculty of rehabilitation, TMSU, on spring 1998. 102 top grade ranking children with normal hearing threshold

Results:1- The thresholds were not significantly different at any frequency (P>0.05) in test re-test trials.
2- The test minus re-test threshold for individual ears showed clinically reliable and acceptable range 0-10dB SPL for at least
99.74% of the ears at all frequencies.
3- The threshold differences between right & left cars in two test sessions were not significantly different (P>0.05) except for 14KHz.
4- High- frequency threshold in two test sessions showed no significant difference between girls & boys at all frequencies (P>0.05) (except for 16 & 20 KHz in right ear and 10 KHz in left ear).
Conclusion: This test can be used for evaluation of individual high-frequency threshold in all frequency as test re-tests tria1. Moreover, this test may use as a beneficial tool for monitoring different endogenous and exogenous auditory pathologies.
Consideration: it is found that this research is valid only among situation of this project. Any generalization needs further research.

Objective: The purpose of study was identify hearing loss in thalassemic patients with history of Desferrioxamine (DFO) therapy. This study was carried out in a cross-sectional descriptive survey on 195 thalassemic patients (3-30 years old) in Gazvin Thalassemia center and Tehran pediatrics&apos medical center.
Methods: The patients underwent routine otolaryngologic history and physical examination, along with standard pure-tone audiometry.
Results: Hearing loss was present in 43.1% of patients. 16% of patients had conductive hearing loss and 4.6% of patient had sensory neural hearing loss. 22.5% of thalassemic patients had high-frequency sensory neural hearing loss and more importantly, high-frequency hearing loss attributable to Desferrioxamine ototoxicity was present in 12% of patients. Furthermore, these evaluations showed that there is a significant relationship between hearing loss and DFO usage and hearing loss too. There is no significant relationship between hearing loss and ferritin level between hearing loss and age of DFO usage too.
Conclusion: Management of these patients requires proper dosing of Desferrioxamine, along with regular otolaryngolgic and audiometric follow-up in order to prevent the effect of ototoxicity of desferal.

Objective: To measure external ear resonant amplitude and frequency in children (3-7 years old) and to compare with adult measures.
Method and materials: The external ear resonance peak amplitude and frequency of 63 children 3-7 years old were recorded. All of the children had normal tympanogram and there was no cerumen in external auditory canal. 20 adult of 21-24 years old (10 male , 10 female) were selected in order to compare with children that had normal tympanogram. The tests included : 1-otoscopy 2- tympanometry 3-microphone probe tube test.
Results: The average of resonance peak frequency for children and adult is 4200 Hz and 3200 Hz , respectively. The resonance frequency of children had significantly diffrence with average of resonance frequency in adults. The average of resonance peak amplitude for children and adult is 17.70 dB and 17.17 dB , respectively.
Conclusion: Resonant frequency and amplitude affect the hearing aid prescription and fitting process and calculating insertion gain so, this measures seem should be considered in children hearing aid fitting.

Background and Aim: 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.
Materials and Methods: 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.
Results: 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.
Conclusion: There is high prevalence of hearing loss among older adults, thus it&aposs 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.

Background and Aim: High incidence of speech disorders in children with cerebral palsy could be related to a deficiency in processing of auditory stimuli. So it is vital to check out any peripheral or central disorders in auditory system using behavioral and electrophysiological auditory tests.
Methods: In a cross-sectional study, 15 children with spastic diplegia, mean age 5.77, SD 2.26 years, and 15 normal children, mean age 5.33, SD 1.80 years, were tested using pure tone audiometry, immittance and auditory brainstem responses. The results were compared between the two groups.
Results: Hearing thresholds and middle ear status were in normal range in all participants however, contralateral acoustic reflex thresholds were mostly elevated. Comparing absolute latency and interpeak latency intervals of auditory brainstem responses between the two groups, absolute latency interval of later waves, and in specific the V wave, was significantly longer in diplegic children (p=0.04) resulting in a longer III-V interpeak latency intervals (p=0.02).
Conclusion: Neurological disorders in ponto-reticulo-spinal pathway, pontine reticular nuclei and upper pons which are adjacent to auditory nuclei of lateral leminiscus and inferior colliculus result in auditory dys-synchrony and increased latency intervals in latter waves of auditory brainstem responses. This could also attributed to functional disorders in wave-generating sites in these patients.

Background and Aim: Internal evaluation is an important part of organization monitoring. One of the Ministry of Health&aposs policies is to encourage educational departments to conduct internal evaluations. The aim of internal evaluation of department of speech therapy was appraising its education, research and treatment qualities and determining its strengths, weaknesses, opportunities and threats (SWOTs) to identify the ways of overcoming weakness and threats.
Methods: This descriptive cross-sectional study was conducted in 10 phases to evaluate 10 factors. Participants were undergraduate, graduate, and postgraduate students, academic staff, director of the department along with the patients. The internal evaluation software for educational and research centers released by Center of Medical Education Studies and Development was modified and utilized. Data was analyzed by calculating mean of means.
Results: Mean of means from highest to lowest scores were respectively as follows: the quality of diagnosis, treatment and dealing with patients 4.15 out of 5 as well as the quality of academic staff 3.5 were in the range of desirable category qualities of management and organizational structure 3.34, graduate students 3.21, teaching and learning processes 3.1, missions and goals 3.09, instructional methods and curriculum models 2.99, educational and research equipments 2.9, students 2.76 and research 2.67 were within the range of rather desirable category. Total score was 3.17 (63.4%) which was within the range of rather desirable category.
Conclusion: The department of speech therapy was in rather desirable state before merger. That result was appropriate according to the department&aposs conditions and supplies.

Background and Aim: The temporal processing is one of the critical features in central auditory processing system the gap in noise (GIN) test is the appropriate clinical tool for appraisal of temporal resolution which in people with multiple sclerosis may encounter with complications. Consequently, the aim of this study was to compare the results of gap in noise test in 18 to 40-year-old patients with multiple sclerosis and normal participants.
Methods: This cross-sectional non-invasive cohort study was conducted on 20 patients with relapsing-remitting multiple sclerosis (mean age: 28.9 years) and 26 healthy normal hearing participant (mean age: 27.7 years) in the age range 18 to 40 years. The approximate threshold and percent of corrected responses were obtained and then were analyzed using Student&aposs t-test.
Results: There was an increase in gap detection and decrease in percent of corrected responses in gap in noise test within multiple sclerosis patients in comparison with normal people (p<0.0001). Moreover, there were a correlation of 78% between increasing disease duration and approximate threshold and also a correlation of 82% between increasing disease duration and corrected responses (p<0.0001).
Conclusion: Based on the findings of this study, it seems that people with multiple sclerosis suffer from some degree of disorder in the temporal resolution which might be due to involvement of central nerve system and, somehow, deficit in central auditory processing. Therefore, for evaluating the temporal resolution in people with multiple sclerosis, gap in noise test could be useful.

Background and Aim: Auditory temporal processing reveals an important aspect of auditory performance, in which a deficit can prevent the child from speaking, language learning and reading. Temporal resolution, which is a subgroup of temporal processing, can be evaluated by gap-in-noise detection test. Regarding the relation of auditory temporal processing deficits and phonologic disorder of children with dyslexia-dysgraphia, the aim of this study was to evaluate these children with the gap-in-noise (GIN) test.
Methods: The gap-in-noise test was performed on 28 normal and 24 dyslexic-dysgraphic children, at the age of 11-12 years old. Mean approximate threshold and percent of corrected answers were compared between the groups.
Results: The mean approximate threshold and percent of corrected answers of the right and left ear had no significant difference between the groups (p>0.05). The mean approximate threshold of children with dyslexia-dysgraphia (6.97 ms, SD=1.09) was significantly (p<0.001) more than that of the normal group (5.05 ms, SD=0.92). The mean related frequency of corrected answers (58.05, SD=4.98%) was less than normal group (69.97, SD=7.16%) (p<0.001).
Conclusion: Abnormal temporal resolution was found in children with dyslexia-dysgraphia based on gap-in-noise test. While the brainstem and auditory cortex are responsible for auditory temporal processing, probably the structural and functional differences of these areas in normal and dyslexic-dysgraphic children lead to abnormal coding of auditory temporal information. As a result, auditory temporal processing is inevitable.

Background and Aim: Temporal lobe epilepsy (TLE) is one of the most frequent epileptic syndromes in adults. Some patients with epilepsy, especially TLE, have central auditory disorders, such as temporal processing, even though they have normal peripheral auditory function. The Gaps-in-Noise (GIN) test is one of the new tests for assessing auditory temporal resolution. The aim of this study was to evaluate temporal resolution ability in patients with unilateral temporal lobe epilepsy.
Methods: In this cross-sectional and descriptive-analytic study, 25 subjects with temporal lobe epilepsy (11 patients with right temporal lobe epilepsy and 14 patients with left temporal lobe epilepsy) and 18 normal control subjects of 15 to 50 years of age were assessed by the GIN test. Parameters of GIN test were analyzed by one-way ANOVA and compared between the three groups.
Results: There was a significant difference in the mean of approximate threshold and percentage of correct answer in GIN test in the right ear, left ear, and mean of both ears between patients with temporal lobe epilepsy and normal subjects (p<0.05). However, difference between right and left temporal lobe epilepsy groups were not significant (p>0.05).
Conclusion: The lower percentage of correct answer and higher approximate threshold in patients with temporal lobe epilepsy in comparison with the normal control group revealed temporal processing deficiencies especially in temporal resolution abilities. This may be due to involvement of structures related to temporal processing.

Background and Aim: It is not known how electrocochleography components of action potentials (AP) and summating potentials (SP) are changed in response to CE-chirp stimulus using extra-tympanic electrodes. This study was done for comparing summating potentials and action potentials specifications in response to CE-chirp and click stimuli.

Methods: Electrocochleography components of action potentials and summating potentials were recorded in 16 normal hearing subjects (8 men and 8 women) aged 22-30 years (mean: 26.7 with SD 2.5 years) with audiometric (250-8000 Hz) hearing thresholds of 15 dB HL or better in response to click and CE-chirp stimulus at 90 dB nHL. Amplitude, duration, latency and area of summating potentials and action potentials and SP/AP amplitude and area ratios were compared.

Results: Among the measured parameters, action potentials amplitude in response to CE-chirp stimulus (0.41 with SD 0.26 µV ) was significantly smaller than action potentials amplitude in response to click (0.61 with SD 0.29 µV ) stimulus (p<0.005). Relative frequency of detecting summating potentials in response to CE-chirp (68.7%) was lower than (100%) click (p<0.005).

Conclusion: Recording electrocochleography component of summating potentials and action potentials with CE-chirp stimulus at high intensity level in normal hearing individuals shows no advantage over click stimulus. Small amplitude of summating potentials as a major problem of extra-tympanic electrocochleography cannot be solved using CE-chirp stimulus.