Fluency & Stuttering Measures

Roger J. Ingham, Sue O'Brian, Richard Martin, Mark Onslow · 2004

Event coding for stuttering-like disfluencies plus the two global ratings the fluency literature actually reports — severity and speech naturalness.

Fluency research runs on two kinds of number: a count of disfluent events in a speech sample, and a global scale rating by a listener. This scheme gives you both, built out of the openly published measurement literature rather than a licensed protocol — the widely used SSI-4 is a proprietary Pro-Ed instrument that requires a licensing agreement, so it is not reproduced here.

Count the events by tagging them. Each stuttering-like disfluency gets its own annotation on the timeline, typed as part-word repetition, single-syllable word repetition, or dysrhythmic phonation. Percent stuttered syllables (%SS) and weighted SLD then fall out of the tags rather than being estimated: weighted SLD is [(part-word repetitions + single-syllable word repetitions) × mean repetition units] + (2 × dysrhythmic phonations), which is why the severity rating on repetition codes is the number of repetition units, not an impression of badness.

Type the typical disfluencies too. Interjections, phrase repetitions and revisions are coded as a separate, presence-only class. This is not busywork: the single most common measurement error in fluency work is sweeping normal disfluency into the stuttered count, and the fix is to give raters somewhere else to put it.

The two global ratings are deliberately kept on their published scales. Stuttering severity is the nine-point scale of O'Brian et al. (2004), and speech naturalness is the nine-point scale of Martin et al. (1984), where 1 is highly natural and 9 highly unnatural. Naturalness exists because fluency-inducing treatments can produce speech that is technically fluent and obviously odd; reporting severity without it hides the trade-off. Both are conventionally averaged over several raters — three for severity, five for naturalness in the classic protocols — so run them as inter-rater-reliability tasks, not single-coder tasks.

A caution about agent assistance. Repetitions and blocks are visible in a time-stamped transcript, but only if transcription preserved them. Deepgram's default output cleans disfluencies away; unless the recording was transcribed with verbatim/filler-word options enabled, the transcript Joey sees has already deleted the phenomenon. Check that before treating agent counts as a starting point, and keep the audio as the authority.

Domains (6)

Part-Word RepetitionPWR

Repetition of a sound or syllable within a word ("b-b-but"). Severity records how many extra repetition units occurred.

Curated skill
Single-Syllable Word RepetitionSWR

Repetition of a whole one-syllable word ("I-I-I went"). Severity records the number of extra repetition units.

Curated skill
Dysrhythmic PhonationDYS

Prolongations, audible or silent blocks, and broken words — disrupted phonation rather than repetition.

Curated skill
Typical DisfluencyTYP

Interjections, phrase repetitions, revisions and abandoned utterances — normal disfluency, coded so it does not inflate the stuttered count.

Curated skill
Stuttering Severity RatingSSR

Global nine-point severity rating of a speech sample, after O'Brian et al. (2004). Conventionally averaged across three raters.

Curated skill
Speech NaturalnessNAT

Nine-point rating of how natural the speech sounds, after Martin et al. (1984), where 1 is highly natural and 9 highly unnatural.

Curated skill
O'Brian S, Packman A, Onslow M, O'Brian N. Measurement of stuttering in adults: comparison of stuttering-rate and severity-scaling methods. J Speech Lang Hear Res. 2004;47(5):1081-1087. Martin RR, Haroldson SK, Triden KA. Stuttering and speech naturalness. J Speech Hear Disord. 1984;49(1):53-58. Einarsdóttir J, Ingham RJ. Have disfluency-type measures contributed to the understanding and treatment of developmental stuttering? Am J Speech Lang Pathol. 2005;14(4):260-273. doi:10.1044/1092-4388(2004/080)

Method- and framework-derived from the open fluency-measurement literature (Martin et al. 1984; Eve et al. 1995; O'Brian et al. 2003, 2004; Einarsdóttir & Ingham 2005). No proprietary instrument is reproduced: the Stuttering Severity Instrument (SSI-4) is a licensed Pro-Ed protocol and is deliberately NOT included, and the disfluency-type definitions and anchor wording here are Tagaroo's own. Cite the sources above.