Abstract
Background and objective: Stuttering is a speech disorder in which the flow of speech is ruptured. Researchers have been studying the phenomenon for years. Valuable information can be gained from quantitative electro-encephalography (QEEG) as an efficient, non-invasive tool with little side effects. The purpose of this study was to compare EEG pattern in stutterers and non-stutterers.
Methods: This study was a descriptive analytical one. Purposive sampling was used to recruit 20 stutters and 20 non-stutters as participants. The research instruments were Stuttering Severity Instrument (SSI4) and Quantitative Electroencephalogram (QEEG) tests.  Independent samples t-test was used to analyze the data.
Results: Significant differences were found in peak frequency indicators (p<0.001), (p<0.001), coherence of waves in right hemisphere (p=0.030), asymmetry (p=0.025) and phase lag (p=0.035) in brain waves between two groups.
Conclusion: It can be concluded that brain wave pattern can be used as an indicator to identify the nature of stuttering. It can also be concluded that the impact of treatment on brain wave pattern is positive, leading to changes and improvements of stuttering.