What does stuttering sound like?

Stutters can sound like a repetition of sounds (b b b brother), syllables (muh muh muh mother) or words (you know you know). Similar to repetitions, the stutter can sound like a stretching of sounds (mmmmmother, and buhhhrother). Additionally, stutters can come in the form of a block, where there is a brief moment where no sound is produced. This can be due a closure of the vocal muscles -- as if you were breath holding-- due to tension.