SSI-4 Assessment
The Stuttering Severity Instrument–Fourth Edition (SSI-4) is a standardized, norm-referenced assessment used to measure observable stuttering severity in children and adults. It examines stuttering frequency, duration, associated physical behaviors, and speech naturalness.
The SSI-4 provides useful information about stuttering behaviors. However, understanding how to interpret these findings alongside the speaker’s experiences is essential for a comprehensive fluency evaluation.
What Does the SSI-4 Assess?
The SSI-4 examines four areas of speech behavior:
- Frequency: Measures the percentage of syllables stuttered (%SS) in speech samples.
- Duration: Measures the average length of the three longest stuttering events, timed to the nearest tenth of a second.
- Physical Concomitants: Evaluates observable behaviors associated with moments of stuttering, including distracting sounds, facial movements, head movements, and movements of the extremities.
- Speech Naturalness: Provides a separate, subjective rating of how natural the speaker’s speech sounds to the examiner.
Frequency, duration, and physical concomitant scores contribute to the overall SSI-4 severity score. Speech naturalness is rated separately and does not contribute to the total severity score.
Administering the SSI-4
The SSI-4 typically takes 15–20 minutes to administer. Depending on the speaker’s age and abilities, assessment tasks may include spontaneous conversation, picture descriptions, and reading. Follow the examiner’s manual for collecting speech samples, identifying stuttering events, calculating percentages, and assigning scores.
During administration, I recommend noting the types of disfluencies observed, such as sound or syllable repetitions, prolongations, and blocks. Also consider physical tension, associated movements, and differences across speaking situations.
Clinical Tip: Stuttering can vary significantly across settings and situations. Consider collecting multiple speech samples, including recordings or observations from familiar environments when appropriate, to obtain a more representative picture of the speaker’s fluency.
Scoring and Interpreting SSI-4 Results
The SSI-4 converts frequency, duration, and physical concomitant measures into a total score, percentile rank, and severity rating ranging from very mild to very severe. These scores describe observable stuttering severity during the assessment.
However, a mild severity rating does not necessarily mean stuttering has little impact on the speaker’s life. For example, a student may demonstrate relatively few stuttering moments during structured testing but avoid answering questions in class or speaking with unfamiliar people. Similarly, a speaker with frequent observable stuttering may feel comfortable communicating and participating in daily activities.
Clinical Tip: Use the SSI-4 to describe observable stuttering behaviors, but do not rely on its severity rating alone to determine functional impact, treatment priorities, or the speaker’s communication needs.
Looking Beyond Observable Stuttering
A comprehensive fluency evaluation should also explore how individuals experience stuttering in everyday situations.
Consider the speaker’s:
- Feelings, attitudes, and beliefs about stuttering
- Avoidance or concealment of stuttering
- Participation in school, work, and social activities
- Communication strengths, priorities, and personal goals
The Overall Assessment of the Speaker’s Experience of Stuttering (OASES) is a helpful companion to the SSI-4. While the SSI-4 measures observable stuttering severity, the OASES examines the speaker’s experiences, reactions, and perceived impact of stuttering.
Using both assessments, when appropriate, can provide a more complete picture of fluency and functional communication.
Writing an SSI-4 Evaluation Report
When documenting SSI-4 results, include the speech samples obtained, types of stuttering observed, relevant scores, associated behaviors, and severity rating. More importantly, connect these findings with the speaker’s experiences and functional communication needs.
Example: Fluency Evaluation Report
The following is a hypothetical example.
“The speaker demonstrated sound repetitions, prolongations, and blocks during conversational and reading tasks. SSI-4 results indicated moderate observable stuttering severity. However, the speaker reported that stuttering affected participation in classroom discussions and increased avoidance of speaking situations. These findings highlight the importance of addressing both observable stuttering behaviors and the speaker’s communication experiences.”
For additional documentation guidance, see my Speech and Language Report Writing article.
Need Help Writing Your Stuttering Evaluation Report?
My Stuttering Assessment Report Templates: SSI-4 & OASES include editable companion templates for both assessments, along with goal banks and recommendations.
Designed for SLPs, clinical fellows, and graduate clinicians, these resources help organize assessment findings and write clear, individualized fluency evaluation reports.
These templates are companion resources and do not include or replace the standardized assessments.
Final Thoughts
The SSI-4 provides valuable information about observable stuttering severity, but a comprehensive fluency evaluation requires more than measuring disfluencies. By considering the speaker’s experiences, communication participation, and personal goals alongside standardized results, SLPs can develop more meaningful recommendations and intervention plans.
The goal is not simply to measure stuttering severity, but to understand the individual and support meaningful communication.