 Studies that are more recent have looked at the effects of DAF in non-stutterers to see what it can prove about the structure of the auditory and verbal pathways in the brain.Indirect effects of delayed auditory feedback in non-stutterers include reduction in rate of speech, increase in intensity, and increase in fundamental frequency in order to overcome the effects of the feedback.Direct effects include repetition of syllables, mispronunciations, omissions, and omitted word endings.