Monday, June 11, 2007

Fluency Disorders

The Measurement of Stuttering Behavior Part II of II

How does one define stuttering?

The answer to this question becomes increasingly important when working with a person who stutters. Over the years, research into stuttering has contributed several ways to define the phenomenon better known as stuttering. Here are 2 of the 5 ways to define stuttering behavior. The clinician should become familiar with the advantages and limitations of each method before using them.

4) Speech Rate
Since stuttering tends to slow down the speech output of a stutterer, one objective way to measure stuttering behavior is to calculate a speakers verbal output rate (speech rate). There are several ways to do
this. One method is to measure the speaker's speech rate in words per minute (wpm). Words per minute is measured by taking the total number of words produced and dividing that by the total speaking time.

For example, John a stutterer has produced 150 words in 2 minutes of speaking time. His average speech rate in words per minute would be 75 (wpm). Bloodstein (1944) found that the oral reading rate of adult stutterers was 123 words per minute. The range for thirty adult stutterers was 42 to 191 words per minute. In comparison, the same material read by a group of non-stutterers produced an average speech rate of 167 words per minute, with a range of 129 to 222 (wpm). Clearly, the verbal output of stutterers was reduced compared to that of non-stutterers.

5) Ratings of Severity
One subjective way of measuring stuttering behavior is via listener perception of speech output. In this measure the listener rates the stutterer's speech output against some rating scale.

For example, the listener would characterize the stutterers speech as mildly dysfluent, moderately dysfluent or severely dysfluent.