Since the time of Demosthenes, we have been searching for a common element among the many immediate, powerful, and natural-sounding fluency enhancement phenomena. A common element which, hopefully, would provide us with insight into a possible causal agent(s) and, of course, would provide for the most effective long-term therapeutic protocol. We suppose there must be an answer to the disorder of stuttering, considering the substantial number of phenomena which immediately eliminate or nearly eliminate stuttering and allow for the production of relatively naturally sounding, fluent speech productions with no conscious effort. Probably an appropriate assumption, since not many disorders, show similar characteristics. In fact, it is probably the ease of amelioration of the overt manifestations of the disorder which attracts so many of us to the province of stuttering research and therapy. To me at least, it seems that the answer must be looking us right in the face, but we lack the "eyes" to see it. Or the "ears" to hear it.
Most recent attempts at trying to find a common element in the inducement of fluent speech have focused on Wingate's notions (1976) and derivations thereof (e.g., Andrews, Howie, Dozsa, &Guitar, 1982; Andrews, Craig, Feyer, Hoddinott, & Neilson, 1983) which stated that fluency was induced via an "altered manner of speaking" which placed an "emphasis on phonation". The problem with Wingate and his followers' notions on fluency enhancement is that they used too expansive a scheme of fluency-not to mention their lack of an operational definition for the fluency inducing gesture. Their description of those physiological events which they consider to be fluent speech production ( e.g., singing, lipped speech, whispered speech, prolonged speech, syllable-stretched speech) in no way, shape, or form should be considered valid. The aforementioned examples of supposedly "fluent speech" in persons who stutter are not congruent with the fluent speech characteristics of nonstutterers. Simply put: singing, lipped speech, whispered speech, prolonged speech, syllable-stretched speech, are not members of the "fluent speech set". This set only includes speech production which is effort-free, natural-sounding and perceptually resembles the fluent speech production of nonstutterers. It is proposed that the only significant characteristics of "true fluency" is that it is indistinguishable from the typical fluent speech of nonstutterers and is "effortless".
In truth, Kalinowski, Noble, Armson, & Stuart, (1994) have provided evidence that shows the fluent post-therapy speech of persons who stutter have been judged to be more "unnatural" than stuttering permeated samples. Or as then AJSLP Editor, Marilyn Newhoff , stated in her commentary of this data set: "What price fluency! (Newhoff, 1994). Yes, Dr. Newhoff, persons who stutter pay a heavy price for stuttering and it appears for fluency too. One might suggest, in a rather radical view, that the post-therapy speech of persons who stutter oftentimes only shows removal of the signature event of repetitions- at least for the most part. However, the signature events of effortful, unnatural sounding, and prolonged speech remain and may be more ubiquitous. This is probably one reason why people who stutter often refuse to comply with efforts to enjoin them in use of the unnatural speech production pattern that clinicians often call "fluent speech", especially outside of the clinical environment. Post-therapy speech is often nothing more than one long monotonous prolongation of syllable structure which permeates all utterances. This stands in contrast to the normal speech of person who stutters which contains natural sounding speech intermixed with occasional repetitions, prolongations, and the assorted ancillary audible struggle behavior. The widely spread prophylaxis of prolonged speech makes for a burdensome task. One that apparently is most difficult to maintain, is relatively unstable, and may be perceptually unpalatable to both listener and speaker alike.
The natural extension of this thesis is that a more befitting schemata of "true fluency" is more likely to generate appropriate inferences about the mechanism or mechanisms responsible for fluency generation and more appropriate therapeutic protocols. Simply put: Are we trying to emulate the "supposed fluency" induced by the motoric targets or are we aspiring to the naturally sounding speech induced by a secondary speech signal? Rationally it follows that causal agents of stuttering are most likely to be found when the generation of fluent speech is not "contaminated" by the artifacts of unnaturalness and effort which is embedded in the speech signal via therapy (see Armson & Kalinowski, 1994). Thus we need to differentiate fluency generators which induce natural-sounding, effort-free speech production and those that do not.
To the best of my knowledge, nobody has found a more effective tool in the inducement of immediate, natural-sounding, effortless, fluent speech in the stuttering population than the speech produced via a "second speech signal" or some derivation thereof. These second speech signals can be choral, shadow, shifted in frequency, and/or delayed temporally in nature. The only specification in this thesis is that the end product is judged to be natural sounding, is automatic and effortless. Choral speech is simply that: a second speech signal which, in some way shape or form, integrates , in a more stable manner, the speech sensory-motor/ perception-production system. All other second speech signals are less powerful, in terms of fluency generation, but most appear to produce natural sounding, effortless, speech.
In a series studies, my colleagues and I have examined the impact of an electronically generated "second speech signal" on stuttering frequency during various tasks (Armson, Kalinowski, Foote, Witt, & Stuart, 1997; Hargrave, Kalinowski, Stuart, Armson, & Jones 1994; Howell, El-Yaniv, & Powell, 1987; Howell, 1990; Kalinowski, Armson, Roland-Mieszkowski, Stuart, & Gracco, 1993; Kalinowski, Stuart, Sark, & Armson, 1996; MacLeod, Kalinowski, Stuart, & Armson, 1995; Stuart, Kalinowski, Armson, Stenstrom, & Jones, 1996; Stuart, Kalinowski, & Rastatter, 1997; Stuart, Miller, Kalinowski, & Rastatter, 1997, Zimmerman, Kalinowski, Stuart & Rastatter, 1997). Our research has demonstrated that fluency enhancement occur for people who stutter under conditions of altered auditory feedback (AAF) One of our studies has examined naturalness and has shown relatively natural speech ratings by speech-language pathologist (White, , Kalinowski, and Armson, J., 1995). These studies need to be continued and expanded into contextually appropriate environments. In addition, the debate about the utility and functionality of an electronically generated "second speech signal" in the treatment protocol remains and is justifiable. Questions about adaptation, generalization, sensitivity, ease-of-use, portability and many others still remain unanswered.
However the thesis of this paper is not to promote, endorse , or promulgate use of AAF as a therapeutic tool for the inducement of natural-sounding, effortless speech. Or to suppose that AAF as a therapeutic tool would generate speech with the aforementioned natural sounding, effortless characteristics. More to the point, this paper is an attempt to continue a discussion of what constitutes "fluent speech" and what mechanisms elicits the most natural speech production with the least amount of effort in our therapy and other contextually relevant environments.
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