Comparing "Mean Length of Utterance" and "Mean Length of Five Phrasal Utterances" between 2-to-5 Year-Old Farsi-Speaking Children

Majid Oryadi Zanjani, Maryam Vahab, Leila Karimi


Background: Since most clinical treatments of Persian children’s language impairments are based on either the therapist, clinicians’ experiences (mostly), or English language norms (sometimes), comparing two minor indices of speech quality, namely “mean Length of Utterance” (MLU) and “mean length of five phrasal utterances” (MLFPU) between different age groups of children, would be unequivocally efficient to help diagnose and treat Farsi-Speaking Children with language impairments.

Methods: To compare the two mentioned indices of 2 to 5-year-old normal Farsi-speaking children, the speech samples of 500 children were scrutinized by elicitation, transcription, and statistically analyzing their language samples.

Results: The net results prove that as the children’s ages grow from 2 to 5, the two mentioned indices increase and extend as well.

Conclusion: The influence of chronological age on the indices varies, regarding the type of language samples. Hence, the analysis of speech quality indices in assessment of children’s language ability has to be performed based on the language sampling methods.


Speech quality indices, richness of vocabulary, mean length of utterance, mean length of phrasal utterances

Full Text:



Dunn M., Flax J, Sliwinski M, Aram D. The use of spontaneous

language measures as criteria for identifying children with

specific language impairment: an attempt to reconcile clinical

and research incongruence. Journal of Speech Hear Research,

; 39(3): 643-54.

Evans JL, Craig HK, Language sample collection and analysis:

interview compared to free play assessment contexts. Journal of

Speech Hear Research, 1992; 35(2): 343-53.

Evans JL, MillerJ. Language sample analysis in the 21st century

Semin Speech Lang, 1999, 20(2): 101-15.

Southwood F, Russell AF. Comparison of conversation, freeplay,

and story generation as methods of language sample elicitation.

Journal of Speech Hear Research, 2004; 47(2): 366-76.

Klee T, Stokes SF, Wong AM, Fletcher P, Gavin WJ. Utterance

length and lexical diversity in Cantonese-speaking children with

and without specific language impairment. Journal of Speech

Hear Research, 2004; 47(6): 1396-410.

Nilipour R. The concrete indices of speech quality assessment.

Journal of linguistics 1992; 9(1): 40-50.

Golpur, L., Nilipour, R., Roshan, B. A comparison between

morphological and syntactic features of 4 to 5 years old in

education severe to profound hearing impaired and normal

children, 2007; 26 (2): 23-29.

Miller J.F, Chapman R.S. The relation between age and mean

length of utterance in morphemes. Journal of Speech Hear

Research, 1981; 24:154-61.

Heiwitt L., Scheffner H.C., Yont K.M., Tomblin J.B. Language

Sampling for Kindergarten Children With and Without SLI: Mean

Length of Utterance, IPSYN, NDW. Journal of Communication

Disorders 38 (2005); 197-213.

Williamson, G. Mean Length of Utterance (MLU), Journal of

Child Psychology and Psychiatry, 2009, 31: 1027–1050.

Oryadi Z.M., Mahmoodi, B.B., Vahab, M., Jafari, S. Efficiency

of picture description and storytelling methods in language

sampling, according to the mean length of utterance index. Journal

of Audiology, 2012, 21(3):18-23.

Jalilevand, N., Ebrahimipur, M., Purqarib , J. Mean length of

utterance and grammatical morphemes in speech of two Farsispeaking

children. Journal of Audiology, 2012, 21(2): 96-108,

Tehran University of Medical Science

Oryadi Z.M. and Ghorbani R.. Study of speech quality indices in

-5 year old Farsi-speaking normal children in cities of Semnan,

Bijand and Tonekabon. Journal of Medical Science and Healing

and Health Services of Mazandaran University, 2005; 15(50):


Bowen C. Brown R. the development of morphology and syntax.

Available from URL: Caroline_


Chengappa Sh, Bhat S, Hiwarale J. Mean length of utterance and

syntactic complexity in the speech of mentally retarded. Language

in India [serial online] 2002 Available from URL: http://www. sep2002/index.html.

Blake J, Quartaro G, Onorati S. Evaluating quantitative measures

of grammatical complexity in spontaneous speech samples.

Journal of Child Language, 1993; 20(1): 139-52. K

Klee T, Schaffer M, May S, Memmbrino I, Mougey K, A

comparison of the age-MLU relation in normal and specifically

language-impaired preschool children. J Speech Hear Disordering

; 54:226-33.


  • There are currently no refbacks.

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.

pISSN: 2345-6167        eISSN: 2345-6159