(1) The student may be identified as having a speech-language impairment if the student has a significant deviation in speech such as fluency, articulation or voice, or in the ability to decode or encode oral language which involves phonology, morphology, semantics or pragmatics or a combination thereof.

(a) The student has a significant deviation in oral performance if the student's performance on standardized test is two standard deviations below the population mean, or between 1.5 and two standard deviations below the population mean, and there is documented evidence over a six month period prior to the current evaluation of no improvement in the speech-language performance of the student even with regular classroom interventions.

(b) For articulation, a significant deviation is consistent articulation errors persisting one year beyond the highest age when 90 percent of the students have acquired the sounds based upon specific developmental norms.

(c) If norm referenced procedures are not used, alternative assessment procedures shall substantiate a significant deviation from the norm.

(2) The student may be identified as having a speech-language impairment only when documentation of the student's interpersonal communication effectiveness in a variety of educational settings by the teacher, parent, speech-language pathologist, and others as appropriate supports the adverse educational effect of the speech-language impairment or oral communication in a classroom or school setting.

(3) The student may not be identified as having a speech-language impairment if the speech or language problems primarily result from environmental or cultural factors.