DURATION PATTERN TEST USING VOWEL /a/ AS STIMULI

DURATION PATTERN TEST USING VOWEL /a/ AS STIMULI Anju Annie Abraham and Dr.Rashmi J Bhat (2011)

The aim of this manual or quick guide is to describe to professionals on how to use, score and interpret the Duration Pattern Test.

The Duration pattern test has good sensitivity and

specificity (86%) with reference to auditory dysfunction ( Museik, Baran & Pinheiro, 1990).

As Duration Pattern test is not limited in its application by the language of the subject or the examiner it can be used in children and individuals with limited or impaired language skills as well. Hence this test was developed using vowel /a/ as the stimuli.

Method: The study was conducted in three phases. In the first phase the stimuli were prepared using long and short vowels -/a/. As the vowel duration is subjective, the average production time of a total of 20 adults (10 males and 10 females) were considered as the standard duration for that particular vowel. The standard stimuli were prepared using three consecutive /a/ in which one varied in duration than the other two with an interstimulus interval of 200 msec (Example: Short /a/ - 200 msec interval- Long/a/-200 msec intervalShort /a/).

The list contained a total of 30 sequences which were presented to each ear and the participants were asked to describe verbally each sequence heard. The participants on the age range of 4-6 years were also asked to do a picture pointing task.

In the second phase, the performances of children with typical hearing abilities for the prepared stimuli were studied. A total of 60 subjects were selected between the age range of 4-8 years with 15 subjects each in the age range of 4-5 years, 5-6 years, 6-7 years and 7-8 years

In the third phase, the obtained results from typical hearing children were compared with performances of five children with Auditory Processing Disorder in the age range between 5 to 10 years

Results:

Typically hearing children showed no significant ear difference. However

significant differences were found among different age groups with the scores improving with age. The mean percentage score for 4-5 years was 67.21, 5-6 years was 72.09, 6-7 years was 87.74 and 7-8 years was 88.41. The performance of children via picture pointing task was poorer than the verbal responses. The mean percentage score through picture pointing task for 4-5 years was 8.21 and for 5-6 years was 11.66. All five children with APD performed poorly and obtained lesser scores than the typically hearing children.

The user is however advised to give a Diagnosis of (C)APD only when performance deficits observed are on the order of at least two standard deviations below the mean on two or more tests in the battery and not to depend only on the results of the present test. However it can be used as a screening tool.