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.

In the current article we will have a look at the evolution of audiological tests. Based on the Olsen's theory, having knowledge about the history of audiological evaluation is not a platitudinous issue, Rather an audiologist should have a comprehensive knowledge about it and be involved in its progress. In this way he can attain enough expertise and science to make use of the technology.The oldest history regarding to this issue goes back to the 16th century, although It should be considered that other related investigations about sound, hearing and related fields has heretofore been performed and the relevant investigators should not be ignored.

 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.

Tactile aids, which translate sound waves into vibrations that can be felt by the skin, have been used for decades by people with severe/profound hearing loss to enhance speech/language development and improve speechreading.The development of tactile aids dates from the efforts of Goults and his co-workers in the 1920s Although The power supply was too voluminous and it was difficult to carry specially by children,  it was too huge and heavy to be carried outside the laboratories and its application was restricted to the experimental usage. Nowadays great advances have been performed in producing this instrument and its numerous models is available in markets around the world.

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.

Background: The current article is aimed at evaluating speech recognition scores in hearing aid wearers to determine whether nonsense syllables are suitable speech materials to evaluate the effectiveness of their hearing aids.
Method: Subjects were 60 children (15 males and 15 females) with bilateral moderate and moderately severe sensorineural hearing impairment who were aged between 7.7-14 years old. Gain prescription was fitted by NAL method. Then speech evaluation was performed in a quiet place with and without hearing aid by using a list of 25 monosyllable words recorded on a tape. A list was prepared for the subjects to check in the correct response. The same method was used to obtain results for normal subjects.
Results: The results revealed that the subjects using hearing aids achieved significantly higher SRS in comparison of not wearing it. Although the speech recognition ability was not compensated completely (the maximum score obtained was 60%) it was also revealed that the syllable recognition ability in the less amplified frequencies were decreased. the SRS was very higher in normal subjects (with an average of 88%).
Conclusion: It seems that Speech recognition score can prepare Audiologist with a more comprehensive method to evaluate the hearing aid benefits.

The word of "Ergonomics "is composed of two separate parts: "Ergo" and" Nomos" and means the Human Factors Engineering. Indeed, Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance. It has applied different sciences such as Anatomy and physiology, anthropometry, engineering, psychology, biophysics and biochemistry from different ergonomics purposes.Sound when is referred as noise pollution can affect such balance in human life. The industrial noise caused by factories, traffic jam, media, and modern human activity can affect the health of the society.Here we are aimed at discussing sound from an ergonomic point of view.

Hearing loss, even when limited to 1 ear, has been indicated as a handicap to communication and learning. Although this does not seem true based on my clinical impressions, there are no objective data available to evaluate, or even infer, what type of hearing loss can become a true handicap to overall academic achievement. Presented herein are findings that imply, although do not prove, the potential academic handicap of unilateral hearing loss. This study prospectively analyzed the audiologic and otologic screening tests in a university over a 9-year period. The University of Tokyo is one of the leading universities in Japan the students examined undoubtedly had academic ability well above average, for the entrance examination is one of the most difficult to pass in Japan. The potential handicap to academic achievement caused by hearing impairment was evaluated by comparing the prevalence of hearing impairment among the study population

Materials and Methods: This study was performed in two parts: included development and standardization of the test and the second part was the evaluation stage. In the first section, Watson&aposs crieria fpr valid speech recognition tests for children was considered. In order to balance the lists phonemically, it was necessary to determine Persian phonemes&apos frequency -of- occurences. Thus, the frequency -of- occurences for 29 phonemes of Persian language in children&aposs and adults&apos speech were separately determined. There were significant differences between some phonemes&apos frequencies in the two samples. So&apos their frequencies in children&aposs speech was used to design the test. It should be mentioned that each list could contains only 25 vowels, while almost 32 ones were meeded according to the phonemically balancing procedure. Therefore, vowels and consonants were separately balanced. The required monosyllabic words were extracted from the books written for 4 to 6 years old children. Finally, four closed set (3- picture matrix) 25 word lists were prepared. The lists were recorded on magnetic cassette in one of the IRIB studios.To assess the test validity and reliabity, 33 normal hearing children were randomly selected from kindergartens over the city of Tehranand were tested at the Audiology Clinic of the Rehabilitation Faculty, Tehran University of Medical Sciences in 1998. The tests included: otoscopy, pure tone & immittance audiometry, establishing speech reception threshold, and speech recognition test - retest by these lists.
Findings: 1- Normal hearing children obtained 92-100 percent scores for each list at their most comfortable loudness levels through test - retest.
2- No significant difference was observed in test - retest scores in each list (p>0.05).
3-No significant difference obtained between the lists test or retest scores (p>0.O5).
4-No significant difference was observed between children&aposs scores in terms of their age and gender (p>O.OS)
Conclusion: this study, therefore, is reliable and valid. The lists are phonemically balanced and equal in difficulty. Due to the conditions under which the test was designed (including, phonemic balance, necessity of using the words that could be pictured and of the presence of tow other word in children&aposs vocabulary which is similar in auditory aspects), only the content validity for word familiarity decreased a little that could be overcome by introducing them through pictures prior to the start of the test.

Background: In recent years there has been increased interest in the use of Al for assessing hearing handicap and for measuring the potential effectiveness of amplification system.AI is an expression of proportion of average speech signal that is audible to a given patient, and it can vary between 0.0 to 1.0.
Method and Materials: This cross-sectional analytical study was carried out in department of audiology, rehabilitation, faculty, IUMS form 31 Oct 98 to 7 March 1999, on 40 normal hearing persons (80 ears 19 males and 21 females) and 40 hearing impaired persons (61 ears 36 males and 25 females, 25-65 years old) with moderate to moderately severe SNI-IL The pavlovic procedure (1988) for calculating Al, open set taped standard mono syllabic word lists, and the real -ear probe- tube microphone system to measure insertion gain were used, through test-retest.
Results: 1/A significant correlation was shown between the Al scores and the speech recognition scores of normal hearing and hearing-impaired group with and without the hearing aid (P<0.05) 2/ There was no significant differences in age group & sex: also 3 In test-retest measures of the insertion gain in each test and 4/No significant in test-retest of speech recognition test score.
Conclusion: According to these results the Al can predict the unaided and aided monosyllabic recognition test scores very well, and age and sex variables have no effect on its ability. Therefore with respect to high reliability of the Al results and its simplicity, easy -to- use, cost effective, and little time consuming for calculation, it&aposs recommended the wide use of the Al, especially in clinical situation.

Watching a speaker's lips is like hearing speech by eye instead of by ear and markedly improves speech perception. In this review I summarise studies over the last sixty years about lip reading, it's issues, methodological problems, experimental and co relational studies, issues of cerebral lateralization, localization and cognitive and neuro psychologic function. Several studies on speech reading in general suggest that hearing impaired groups actually do not possess superior speech reading skills compared to normal controls. With function magnetic resonance imaging (FMRI) it was also found that the linguistic visual cues are sufficient to activate auditory cortex in the absence of auditory speech sounds. Here I presented data and arguments about all aspects of the phenomenon of lip reading and it's use in rehabilitation audio logy

Method & Material: This study examined the speech in noise test in 60 school age children with otitis media with effusion and 30 school age children with normal hearing in +5, 0 and -5 dB signal to noise ratio. The mean of age was 8.05 in study group and 8.25 in control group. Speech in noise test were performed for study group and control group in quiet an in noise. Speech noise presented ipsilaterally in both groups.Finding: The correlation of mean of SDS in +5, 0 and -5 dB signal to noise ratio between study group and control group, is significant.

Cochlear implant is the result of a great combination and collaboration of engineering and medicine. It is mainly because it has the most conflict with the human nervous system among all prosthesis. Cochlear implant helps a child with profound hearing loss to understand and articulate speech and let an adult person with hearing loss communicate with people by phone. Although these wonderful results could not be seen in all patients, will let us know about the great scientific findings.

This case can be placed in a neurologic classification. The patient is a child with learning disability in school activities. He was first referred to an audiological clinic because of a central auditory processing disorder (CAPD). His mother has noticed several hearing problems and this led us to the evaluations for his central auditory processing disorder. He has problems in hearing speech in noise and speech processing and need his friends repeat words during communication. no vestibular disorder was noticed nor any localization problem. The child has a good progress in school and only suffered problems in reading tasks. Intelligence quotient(IQ) was also normal.

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There is a general belief that speech perception training and specifically speechreading training for adults with acquired hearing impairment is very useful. Numerous researchers have mentioned that visual cues play an important role even in speech perception of people with normal hearing. In this review article publications and rasearch of different years on lipreading training have been have been reviewed.

Background and Aim: Hearing loss results in impairment of  muscles coordination and survival essential that are engaged in motor speech timing tasks. It will negatively affect the acquisition of speech sounds. The purpose of this study was to compare the oral diadochokinesis in normal-hearing and hearing - impaired adolescents
Materials and Methods: This research was conducted on sixty-one adolescents aged 15-18 years old. Forty-six had moderately severe, severe, or profound hearing loss and fifteen were normal. The time spent to perform each oral diadochokinesis tasks was measured by speech analyzer of Dr. speech software, version four.
Results: Results indicated that hearing - impaired performed significantly slower on all speech timing tasks than their normal hearing peers except those with moderately severe hearing-impaired group. There were significant differences between profound hearing-impaired group and both other groups.
Conclusion: The results of this study point out  the motor speech problems in hearing impairment. The differences, in general, indicate that speech-timing coordination deficits are compromise with hearing loss degree.

Background and Aim: Central auditory processing disorders (CAPD) may have a variety of etiologies therefore, performing CAPD tests seem inevitable. Behavioral tests such as synthetic sentence identification (SSI) has gained considerable popularity because of high sensitivity to brainstem and cortical lesions, high diagnostic ability,  cost-benefiting, and also limitations of electrophysiologic tests. The purpose of this study was to prepare a Farsi-language version of SSI and to perform a primary evaluation. 
Materials and Method: Farsi SSI test was made and recorded on CD. Then sixty 20-to 35- year old normal-hearing participants were evaluated in audiology clinic, Faculty of Rehabilitation Sciences Iran University of Medical Sciences in three months.
Results: There is no significant difference between scores of Farsi and original versions of SSI. Gender has no significant effect on the scores.
Conclusion: According to this results, Farsi SSI is comparable to the original one. It can, therefore, be used in CAPD test battery.

Background and Aim: The purpose of this research is to study the standardization of speaking and reading rates in a group of normal speaker of female students, and to compare them. As the rate of speech is an important variable in the evaluation and treatment of stuttering, cluttering, dysarthria and apraxia.

Materials and Method: One hundred of second grade students of primary school and an equal number of fifth grade students participated in this study. All subjects were native speakers of Farsi, who passed an informal, screening test of articulation and speech. None of the subjects had a history of speech, hearing, or neurological disorders. The subjects were asked to read from the 180 words portion of their Farsi book and tell story. Their speech was recorded by using a tape recorder. Then the data were analyzed for word and syllable rate. In transcribing the samples, single morpheme was counted as single word and compound words were counted as two words if they had two free morphemes. Non-word interjections were excluded from word and syllable counts while word interjections and repeated words were included in the count. Independent t-test and paired t-test were used for analyzing.

Results: In the second grade students the reading rate is, on the average, 189.4 syllable per minute (SPM)(94.9 word per minute(WPM), 3.1 syllable per second(SPS)) and the talking rate is 189.8 SPM (99.1 WPM, 3.1 SPS) and in the fifth grade student the reading rate is 223.9 SPM (119.0 WPM, 3.7SPS) and the talking rate is 210.26 SPM (109.5 WPM , 3.4 SPS).

Conclusion: The result highlight that in the fifth grade students, reading rates are higher than talking rates while in the second grade they are not, because they do not have enough skills for whole word reading. A remarkable finding in this research is that, reading and talking rates in the fifth grade students are higher than the second grade students.

Background and Aim: Nowadays, auditory perception is not a complete method to assess vowels quality and we need to use more objective instruments.In this study we want to determine and compare the persian vowels formants in normal and hearing Impaired students in 7ـ9 year old children of Isfahan.
Materials and Methods: This cross sectional study was performed on 64 normal and hearing impaired students. Background information was by interview and then, vowel production test was performed. First three formants of each vowel were obtained and recorded by speech studio soft ware and Dr. Speech device Data were compared between groups.
Results: Mean F₁ and F₂, and F₂/F₁ and F₃/F₁ ratio of Persian vowels between these three studied groups were different significantly. Mean F₃ of /o/, /e/ and /a/ in all groups was different significantly. Although we could not find such a significant differences for /u/, /i/ and /æ/ between these groups(p<0.05).
Conclusion: The most important difference between normal and hearing impaired children is their vowel Space, and we found that, the more sever the hearing impairment is, the closer vowel space will be seen. The hearing impaired children rely mostly on their proprioceptive sense because of their hearing deficiency and it causes less movement of the tongue, so they usually substitute vowels which have similar F₁ and F₂.