Background and Aim: Human’s voice is observable and measurable like his other behaviours. Investigations have shown that characteristics of voice differ in males and females and possibly in different languages. Clinically, knowing natural voice characteristics is helpful for distinguishing voice pathologies. So the purpose of this study was to measure and compare the fundamental frequency human voice.

Materials and Methods: subjects were young males and females of Iranian Fars, Turk and Kurd races. First the subjects were asked to read some Persian sentences , then their voice samples were analysed by Dr.Speech software.

Results: Fundamental frequency mean is 168±46 Hz and 120±48 Hz for females and males , respectively , which shows significant difference. There is no significant difference between fundamental frequency mean of different races.

Conclusion: There is significant difference between fundamental frequency of males and females , but this difference is not attributable to their mother tongue. Key words: voice, fundamental frequency, Iranian, Fars , Turk , Kurd.

Background and Aim: Agrammatism is a phenomenon of neuropsychological relevance which has been recently investigated from conceptual and empirical aspects. The present study focuses on grammatical deficit in agrammatic aphasia. We evaluated the impairment of correct use of tenses of Persian verbs in agrammatic Broca&aposs aphasia.
Methods: Eight patients (mean age 57 years) participated in this descriptive - analytic study. They were classified as agrammatic Broca&aposs aphasia according to the Persian aphasia test, their CT Scan and MRI reports and other inclusion criteria. All patients but one were monolingual native speakers of Persian (Farsi). The other individual was bilingual whose dominant language was Persian. All subjects had a left unilateral brain lesion for at least one year after the onset of brain damage. The written sentence completion and picture sentence completion tests were designed and performed.
Results: Results do not indicate significant difference between Past Tenses of verb however, comparison of means showed best scores in Simple Past, Past Continuous, Present Perfect and Past Perfect, respectively. A main result of this study was significant difference between the mean of responses to Past Tense in comparison with Present Tense and Future (p=0.02).
Conclusion: Use of tense is impaired in agrammatic Broca&aposs aphasia in Persian. Our findings point out that use of Past Tense is impaired significantly more than the other tenses of verb.

Background and Aim: Understanding and defining developmental norms of auditory comprehension is a necessity for detecting auditory-verbal comprehension impairments in children. We hereby investigated lexical auditory development of Persian (Farsi) speaking children.
Methods: In this cross-sectional study, auditory comprehension of four 2-5 year old normal children of adult&aposs child-directed utterance at available nurseries was observed by researchers primarily to gain a great number of comprehendible words for the children of the same age. The words were classified into nouns, verbs and adjectives. Auditory-verbal comprehension task items were also considered in 2 sections of subordinates and superordinates auditory comprehension. Colored pictures were provided for each item. Thirty 2-5 year old normal children were randomly selected from nurseries all over Tehran. Children were tested by this task and subsequently, mean of their correct response were analyzed.
Results: The findings revealed that there is a high positive correlation between auditory-verbal comprehension and age (r=0.804, p=0.001). Comparing children in 3 age groups of 2-3, 3-4 and 4-5 year old, showed that subordinate and superordinate auditory comprehension of the former group is significantly lower (p<0.05) than the others . Intra-group comparisons revealed no significant difference between nouns, verbs and adjectives (p>0.05), while the difference between subordinate and superordinate auditory comprehension was significant in all age groups (p<0.05).
Conclusion: Auditory-verbal comprehension develop much faster at lower than older ages and there is no prominent difference between word linguistic classes including nouns, verbs and adjectives. Slower development of superordinate auditory comprehension implies semantic hierarchical evolution of words.

Background: Children usually produce their first words when they are 10-15 months old and go through simple to complex speech by passing some stages. One of the criteria for examining development of children's language is mean length of utterance (MLU). The main purpose of this study was calculating mean length of utterance and grammatical morphemes used by Farsi-speaking children during their 12-60^th months of life.
Case: It was a longitudinal descriptive study. Every month during children's 12 to 60^th months of life, 120-minute spontaneous speech samples of two children in kindergarten were videotaped and transcribed. The girl said her first word at the age of 12, and the boy said his first word at the age of 16 months. Combining words and constructing two-word utterances started at 18 and 20^th months of the girl's and the boy's lives respectively. First grammatical morpheme appeared before the 24^th month of children's lives and when mean length of utterance was lower than 2 morphemes. Singular verb suffixes were acquired sooner than the plural ones. Both children started using six subject identifiers of Farsi language before 36^th month of their lives.
Conclusion: The speech development in Farsi-speaking children follows the same pattern as other children, starting from one-word utterances and complicates gradually by increasing the number of words, word combinations and using grammatical morphemes. The important point is that Farsi-speaking children started to use grammatical morphemes when their mean length of utterance was lower than two morphemes.