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It has been shown that cochlear implant significantly improves verbal communication in deaf children. The aim of the current study was to investigate and compare the verbal and non-verbal communication abilities in two groups of deaf children: without cochlear implant (CI), and children using CI for 12-24 months. The results were then compared with typically-developing children as the control group.

87 children participated in this cross-sectional, descriptive analytical study, (14 deaf children without CI, 25 children with CI that their hearing ages were 12 to 24 months and 48 normal children aged 12 to 24 months). A reliable verbal and non-verbal checklist was completed by parents and nonparametric method was used for data analyzing.   

The results indicated that non-verbal communication skills were similar in all groups with no significant difference (P>0.05). However, verbal abilities in deaf children without CI were significantly impaired compared to the children with CI and control group (P<0.05). Furthermore, there was no significant difference between the verbal communication scores of children with CI and normal children (P>0.05). 

It can be expected that deaf children who receive CI, will reach the verbal communication abilities of 12-24-month-old typically children, at least 12 to 24 months post-implantation

Although cochlear implantation has been proven to cause considerable improvement in perceptive and expressive language of prelingually severe to profound hearing–impaired children, however, children with cochlear implant have grammar and vocabulary deficits depends on some factors such as diagnosis age, acoustic approval age, hearing age, rehabilitation onset and etc. The purpose of this study was to measure children's lexical diversity and syntactic complexity after cochlear implant in persian speaking children.
This study included 10 children with cochlear implant and 10 age- and gender-matched normal hearing children. In order to collect data, language samples of children were gathered via picture description. The first 50 utterances were analyzed to measure mean lentgh of utterances, number of different words, number of total words and type token ratio. Mean hearing age of participants was 67.7 months (SD=1.77) and we used independent T test for data analysis.
There was no significant difference in all measures between children with cochlear implants and hearing age peers (p>0.05).
Duration of hearing experience after CIs is an important factor for acquiring speech and language abilities. In other words, after 60 to72 months of implant experience, their lexical diversity and syntactic complexity were almost similar to chronological age scores of 60 to 72 months in normal hearing children.

Vowel perception occurs through the spectral and temporal information transference. Presence of temporal information in the envelope makes the speech signals perceivable, even when spectral information weakens in the synthesized signals. The present study deals, for the first time, with determining and comparing the acoustic characteristics of clear and vocoded vowels of the speakers of English and Persian languages. Ten native Persian (5 female and 5 male) and one male native English speakers produced their simple vowels of their mother tongue for three times. Tokens were of 180 Persian and 24 English phonetic samples. The vowels were then vocoded using MATLAB software and 270 Persian Vocoded samples and 54 English Vocoded samples were extracted. The waveforms, spectrograms and LPC diagrams of clear and vocoded vowels were analyzed using the Praat software. Results showed that in Persian speakers F0, F1, vowel space and duration of clear vowels were higher for females than males but the intensity was lower. Formant frequencies for F1-F3 were different across two languages. Vowel space was greater in Persian and English vowels duration and intensity were longer and lower respectively. In both languages, F0 and formants of vocoded vowels were not identifiable, and their LPC diagrams had rounded peaks with lower amplitudes. Duration of clear and vocoded vowels was similar, but intensity of the latter decreased in Persian and enhanced in English. Results showed spectral differences between vocoded and clear vowels in both languages.

Aural rehabilitation program after a cochlear implant leads to improve the auditory performance of hearing impaired children. The present study aims to determine the effect of cochlear implants and aural rehabilitation program in the auditory development of children with cochlear implants (CI). This longitudinal analytical study was conducted on 15 deaf children (m. a. 45. 27 mo) who received CI in the AmirAlam cochlear implant center between August 2010 and January 2011. Auditory skills of deaf children were assessed before they received CI، and then again 2، 4، 6 and 8 months after implantation. Data was collected by interview with parents of deaf children. Newsha developmental scale is used for this purpose. After determining the developmental age، Pretest Developmental Rate، Intervention Efficiency Index and Proportional Change Index were calculated. One-way ANOVA and LSD post hoc tests were used for analysis of data. There was a significant increase in Pretest Developmental Rate during the aural rehabilitation after a cochlear implantation (p<0. 0001). There was a significant difference among the 4 follow up assessments of Intervention Efficiency Index (P<0. 0001). There was also a significant difference among the 4 follow up assessments of proportional change index (P<0. 0001). Aural rehabilitation program after a cochlear implant can accelerate the development of auditory skills of children with cochlear implants، which in turn results in acquire skills close to normal hearing peers.

Early diagnosis of hearing loss lead to early intervention and improvement of developmental skills of children with hearing loss. The present study aimed to determine the mean age of hearing loss diagnosis and cochlear implantation (CI) in hearing impaired children and to compare the age of performing cochlear implantation in children who were identified by newborn hearing screening with those who were not.

This cross-sectional study was conducted on 96 children with severe to profound sensorineural hearing loss who received cochlear implantation in Amir-e-Alam cochlear implantation center between the years 2008 and 2010. For data gathering، we assessed subjects'' medical archives، interviewed with their parents and took medical history including demographic information، birth history and hearing loss history.

Mean age of hearing loss suspicion، diagnosis، hearing aids administration، Initiation of rehabilitation program، performing cochlear implantation and mean age when cochlear implantation was utilized were 6. 73 (SD=5. 79)، 9. 35 (SD=5. 79)، 13. 41 (SD=6. 10)، 16 (SD=6. 36)، 41. 25 (SD=11. 12)، and 42. 15 (SD=11. 00) months، respectively. There was statistically significant difference between them (p<0. 05). 43. 8% of hearing impaired children had been identified by newborn hearing screening. There was statistically significant difference between cochlear implantation operation age of children who were identified by newborn hearing screening with those who were not (p<0. 0001).

In spite of notable reduction in the age of hearing loss diagnosis and intervention during recent years، compared to international indices it is still tardy. Conducting newborn hearing screening can significantly reduce these ages.

Due to defects of auditory feedback، children with hearing loss have inappropriate speech intonation. Consistently، results of previous studies have shown that cochlear-implanted children have some difficulties in their intonation. Intonation shows the type of the sentence which can be statement or question sentences. The purpose of this study was comparison of speech intonation in cochlear-implanted children and normal hearing children.

The present study was performed on 25 cochlear-implanted children and 50 normal hearing children. Different pictures were shown to the subjects and they said statement and question sentences. All sentences were heard by eight speech therapists and perceptually judged. Using praat software mean base frequency and pitch alterations were measured.

In cochlear-implanted group، mean speech base frequency was higher and mean pitch alteration was lower than the control group. Mean experts'' scores in cochlear-implanted group were lower than the control group. Differences in all three variables were statistically significant (p<0. 05). There was a significant direct correlation between duration of time that the children had cochlear implant and perceptual judgment scores (p<0. 05).

According to the results، cochlear implant prosthesis has limited efficacy in improving speech intonation; although their ability to produce speech intonation improves by increasing duration of the time that children have cochlear implant. Thus speech therapists should consider intervening on speech intonation in treatment program of cochlear-implanted children.

Cochlear implant (CI) and aural rehabilitation result in speech and cognition skills development of children with hearing impairment. The aim of this study was to investigate effect of aural rehabilitation on speech and cognition development in children using cochlear implant. In this longitudinal study, parents of 15 hearing impaired children (m.a. 45.27 mo) who received CI in AmirAlam CI center between August 2010 and January 2011 were asked by Newsha developmental scale. Assessments were performed before CI operation and then again every 2 months for a period of 8 months after implantation. Developmental age of children in each of speech and cognition skills was determined. Then Pretest Developmental Rate, Intervention Efficiency Index and Proportional Change Index were calculated. A significant difference was observed among Pretest Developmental Rate in the pre intervention and 4 follow up assessments in each of speech and cognition skills (P<0/0001). There had not been a significant difference among the 4 follow up assessments of Intervention Efficiency Index in speech skill (P=0/210). There was a significant difference among the 4 follow up assessments of Intervention Efficiency Index in cognition skill (P<0/0001). There had been also a significant difference among the 4 follow up assessments of Proportional Change Index in each of speech and cognition skills (P<0/0001). Aural rehabilitation can facilitate speech and cognition development of children with CI which in turn makes possible achievement of age-appropriate developmental levels.

In neural response telemetry, intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation send to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential, is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating of the potential's slope of amplitude growth function changes in three monthes after receiving the devise in pediatric cochlear implant recipients. This longitudinal study evaluated the potential's slope of amplitude growth function changes in four given electrodes in four sessions after receiving the devise by approximately one month's intervals in all of the children who implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December. Friedman test used to analysis of results. Electrically evoked compound action potential's mean slope of each electrode was more in later sessions relative to first session, while there was significant difference between the 1st and the other electrodes’ responses in every session(p<0.05). The reliabiliy of the responses result in more certainty of clinician to fit the speech processor for along time. Better responses in apical electrodes may lead to develope an effective coding strategy.

Although the ability of speech perception has been improved in implanted subjects with recent progress in technology, cochlear implantation alone is not enough and more aural rehabilitation is necessary. The aim of this study was to assess improvement of speech perception in children with cochlear implant. Fourteen cochlear implanted children with a mean age of 5.5 years participated in this study. Auditory training was performed in 10 to 43 sessions. Speech recognition and perception were evaluated every 3 months. Third evaluation was done only for 4 patients. Mean total score of the first evaluation was 43.21%, of the second was 63.76%, and of the third evaluation was 78%. All children obtained complete score for sound awareness at the first evaluation. In environmental sounds discrimination, 71.3%, 84.36%, and 100% answered completely to the questions of three evaluations respectively. In speech sounds discrimination, 34.7% in the first, 57.04% in the second, and 85% in the third evaluation obtained the complete score, and in auditory memory, complete responses were 21% for the first, 57.12% for the second, and 83% for third evaluation. In story rephrasing and comprehension, no one answered to questions completely. However, 12.83% obtained the complete score in the second and third evaluations. There were statistically significant differences between the first and the second evaluation (p=0.002(. Sound awareness ability seems to be achieved rapidly. Development of speech and environmental sound discrimination abilities, particularly speech comprehension which is the most important skill, need more impressive training.

Intonation perception mainly relies on fundamental frequency changes perception that is not available for individual with profound to severe hearing loss. The aim of the present study is to investigate the perception of intonation in cochlear implanted children and compare with normal hearing children.

This study has been carried out on 25 cochlear implanted children and 50 children with normal hearing. An adult who her first language was Persian, expressed some questions and statement sentences. These sentences were playing for child and was asked him/her to determine whether it was in a question form or statement one.

The results showed that perception of question and statement sentences intonation had significantly differences between two groups (P<0.05). Perception of question and statement sentences intonation had significantly correlation with age at implantation and duration of implant use (P<0.05).

According to the findings of the current study and previous studies, cochlear implant has some deficits in facilitating the perception of intonation. However, this limitation has been compensated partly for early surgery. Thus, speech language pathologists should consider intervention of intonation in treatment program of cochlear implanted children.

Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals. Thirty-three unilateral cochlear implanted patients (mean age 19.96 years) and 30 normal hearing individuals (mean age 24-27 years) as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups. Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48%) from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear. Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

In neural response telemetry (NRT), intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation send to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential (ECAP), is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating of the potential's threshold changes in three monthes after receiving the devise in pediatric cochlear implant recipients. This longitudinal study evaluated the potential's threshold in four given electrodes in four sessions after receiving the device by approximately one months intervals in children implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December. ECAP mean threshold level of each electrode did not significantly change in differnent sessions, while there was significant difference between apical and basal electrode's responses in every session(p<0.001). The reliabiliy of the responses result in more certainty of clinician to fit the speech processor for a long time. Better responses in apical electrodes may lead to develope an effective coding strategy.

ntroduction: There are contradictory reports regarding vestibular function after cochlear implant surgery. In this study, we evaluated the influence of cochlear implant surgery on vestibular function by comparing the results of caloric test in both ears of patients who received implants. 24 adult patients who had undergone cochlear implant surgery at least 6 months earlier, were participated in this study. Caloric test with the stimulus of cold and warm water was performed on both ears of each patient and results were compared with each other regarding unilateral weakness, directional preponderance and areflexia. The differences between two ears regarding directional preponderance, unilateral weakness and areflexia were not statistically significant. It seems the pathological cause of deafness is a more influential factor on vestibular dysfunction than the damage following cochlear implant surgery.

Although it is not a new disorder, in recent times we have attained a greater understanding of auditory neuropathy (AN). In this type of hearing impairment, cochlear hair cells function but AN victims suffer from disordered neural transmission in the auditory pathway. The auditory neuropathy result profile often occurs as a part of that of the generalized neuropathic disorders, indicated in approximately 30-40% of all reported auditory neuropathy/auditory dyssynchrony (AN/AD) cases, with approximately 80% of patients reporting symptom onset over the age of 15 years. In the present report, the results of audiologic tests (behavioral, physiologic and evoked potentials) on two young patients

Auditory steady state response(ASSR) is an auditory evoked response that has received a lot of attention nowadays. At present, ASSR is mostly used to estimate pure-tone thresholds. Clinical evidence of ASSR in combination with findings for auditory middle latency response (AMLR) and 40 Hz response support the assumption that based on stimulus modulation rate, the ASSR anatomic generators are sub-cortical and/or cortical. The goal of the present study was to investigate ASSR findings in a group of young adults with auditory neuropathy/dys-synchrony(AN/AD). Patients and This cross-sectional analytical study was performed on 16 adults with AN/AD (mean age: 20 5.30 years) and 28 subjects with normal hearing(mean age: 22 3.80 years). ASSR test with high rate modulated stimulus was done at four octave frequencies of 500, 1000, 2000 and 4000 Hz on each ear individually in both AN/AD and control groups. Independent t-test was used to compare hearing thresholds obtained by behavioral evaluation and ASSR recording in each studied group individually. Average pure-tone thresholds revealed moderate hearing loss in AN/AD individuals with focus on low frequencies so that the low-tone loss seen in audiograms was observed in almost two-thirds of the subjects, a finding which is common in adults with AN/AD. However, ASSR revealed profound hearing loss at four studied frequencies in all AN/AD patients regardless of behavioral hearing thresholds, and a significant difference was shown between hearing thresholds gained by these two methods, namely PTA and ASSR. Although in clinical setting ASSR is usually used to estimate hearing thresholds in different populations and degrees of hearing loss, its findings are different in AN/AD patients and can be used for differential diagnosis of this disorder. Using high rate modulated stimulus, severe and profound hearing loss or no ASSR is expected in AN/AD. Considering the fact that ABR also leads to the same abnormal results in AN/AD, it seems that the brain generators of both ABR and ASSR are the same and the concordance between their findings can confirm a defect in auditory brainstem function in patients with suspected AN/AD.

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.

The main result of hearing impairment is reduction of speech perception. Patient with auditory neuropathy can hear but they can not understand. Their difficulties have been traced to timing related deficits, revealing the importance of the neural encoding of timing cues for understanding speech.

In the present study psychoacoustic perception (minimal noticeable difference in intensity, frequency and time), and word discrimination ability of young patients with auditory neuropathy was compared with normal controls.

This cross-sectional analytical study was performed on 16 young right-handed people with auditory neuropathy, (mean age 20±5.30 years), and on 28 subjects with normal hearing, (mean age 22±3.80 years). The minimal noticeable difference in sound intensity, frequency and time were measured by conducting "intensity discrimination'' and "gap detection" tests at supra-threshold levels and "frequency discrimination" test at different octave band frequencies in both groups. The word discrimination score was measured in silence and in three different signals to noise. Results of tests were compared between two groups.

Significant difference was shown between patients with auditory neuropathy and control subjects in gap detection (at all intensity levels), frequency discrimination (in all octave band frequencies) and intensity discrimination tests at all intensity levels, (p<0/003). The word discrimination score was decreased in the presence of noise in three different signals to noise ratios of zero, +5 and +10 dB in both groups, and there was a significant difference between results of word discrimination test in patients and controls in both silence and different levels of noise.

The results showed that people with auditory neuropathy have a deficit in temporal processing and poor frequency discrimination. Severe impairment in temporal processing is probably the major factor contributing to poor speech recognition in people with this disorder. This data not only demonstrates the importance of neural synchrony for auditory perception, but also provides guidance for better diagnosis and treatment of auditory neuropathy.

Physiologic measures of cochlear and auditory nerve function may be of assis¬tance 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 co-chlear responses (otoacoustic emissions and cochlear microphonics) and auditory brainstem response in some adults with auditory neuropathy/ dys-synchrony and subjects with normal hearing. Patients were 16 adults (32 ears) in age range of 14-30 years with auditory neu¬ropathy/ 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. The pure-tone average was 48.1 dB HL in auditory neuropathy/dys-synchrony group and the fre¬quency of low tone loss and flat audiograms were higher among other audiogram's shapes. Transient oto¬acoustic 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 co-chlear microphonics response were higher in auditory neuropathy/dys-synchrony patients than control peo¬ple 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. Audi-tory brainstem response had no response in auditory neuropathy/dys-synchrony patients even with low stim¬uli rates. 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 emis¬sions and cochlear microphonics responses to measure cochlear hair cells function are suggested in them.

Loss of speech perception is a major effect of hearing impairment. In many cases with "auditory neuropathy", speech perception sustains severe impairment and is disproportionate with behavioral pure-tone average. In a primary audiologic evaluation, there is usually no auditory brainstem response (ABR) or acoustic reflex, while the cochlear function is within normal range. Patients with auditory neuropathy exhibit impairments in psychoacoustic evaluations, and their difficulties in sound temporal processing are due to the dys-synchrony of their auditory nerve fibers. This cross-sectional analytical study was performed on 16 young adults with auditory neuropathy and 28 normal hearing subjects. In both auditory neuropathy and control groups, auditory middle latency response (AMLR) and auditory late response (ALR) were recorded and psychoacoustic measurements including "intensity discrimination", "frequency discrimination", and "gap detection" as well as a word discrimination test in silent and in three different signal-to-noise ratios were carried out. There was no agreement between the pure-tone average (PTA) and word discrimination score (WDS). Despite AMLR absence in 6 patients, auditory late response ALR was recorded in all the individuals and there was a significant correlation between some characteristics of these responses and the word discrimination score. The patients revealed remarkable impairment in the discrimination of intensity, frequency, and temporal characteristics of sound. In addition, there was a significant correlation between each of these characteristics and WDS. The WDS showed considerable variability in individuals with auditory neuropathy and decreased in the presence of noise considerably. It seems that neural synchrony had different representations in short (and middle) auditory evoked responses by comparison with late ones. Auditory neuropathy patients’ difficulties in discriminating the intensity, frequency, and temporal characteristics of sound and their relation with WDS showed eight nerve functions in processing these psychoacoustic perceptions and their effects on speech understanding.