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Reviewing the Evidence

Vol. 17 •Issue 36 • Page 6
Reviewing the Evidence

Gregory Lof's critical take on oral-motor therapy

Gregory Lof, PhD, CCC-SLP, has always had an interest in controversial therapy treatments. He followed the controversy over facilitated communication in the 1990s and authored a paper questioning the efficacy of auditory integration training.3 But when the issue of non-speech oral-motor exercises (NS-OME) to change speech sound production surfaced in his area of specialty—articulation and phonology—he decided to take an active role in evaluating the efficacy of the proposed treatment technique.

For the past eight years Dr. Lof, an associate professor and acting director of the graduate program in Communication Sciences and Disorders at the MGH Institute of Health Professions, in Boston, MA, has closely followed the dialogue about the use of NS-OME to change speech sound productions.

"When this area started rearing its head, I became interested in trying to evaluate it systematically, philosophically and theoretically and in using the literature to see what was out there," he told ADVANCE.

Along with colleague Maggie Watson, PhD, CCC-SLP, of the University of Wisconsin-Stevens Point, he conducted a nationwide survey to gauge the popularity of using NS-OME as a speech sound production treatment.2 Their results indicated that 85 percent of the 537 clinicians surveyed use NS-OME with the goal of changing speech sound production.

Three Canadian speech-language pathologists also conducted a study on this issue and received theexact same 85 percent response from a pool of 535 participants.1

In an accompanying literature review Dr. Lof did not find any evidence of NS-OME being effective in changing speech sound production. "I could find no evidence whatsoever that there was any benefit," he stated.

His survey results became widely known after he was invited to present them at the American Speech-Language-Hearing Association (ASHA) Convention last year in Miami, FL. The presentation drew a standing room-only crowd. His hand-out for the presentation attracted even more attention after it was made available on the ASHA Web site.

While the research base surrounding NS-OME is small, it still can be evaluated using critical, scientific thinking and best practices, he said. If good evidence is lacking for or against a particular therapy, that therapy can be examined using the theory and philosophy of its underpinnings.

"When you look at the theory behind non-speech oral-motor exercises, it's very weak," he stated. "We have very little data, but what data we do have show that it doesn't work."

Dr. Lof dissected the theory behind the exercises, noting that non-speech tasks are likely to change non-speech behavior, while speech tasks should change speech behavior.

"The bottom line is that working on non-speech behaviors will not affect speech," he stated. "It's called task specificity. You can use the same oral structures for different tasks such as eating, speaking and swallowing, but the same structures are not going to work the same for the different tasks."

Task specificity likely is linked to the natural organization mechanism of the brain, which is focused on tasks rather than muscle groups, he explained. "Working on a certain set of non-speech muscles isn't going to work for speech. Those muscles aren't going to work the same as they do for speech. There is evidence to show that that's true."

At the center of the debate over the use of NS-OME for speech sound production is the shift of speech-language pathology to an evidence-based profession and the more stringent research requirements that entails.

In the survey he conducted with Dr. Watson, 87 percent of the respondents reported that they learned to use NS-OME from non-peer-reviewed sources, and 61 percent agreed with the statement, "The literature I have read strongly encourages the use of NS-OME."

These statistics represent a need for a clearer understanding of evidence-based practice among practicing clinicians, Dr. Lof said. "One of the things that bothers many of our research clinicians the most is that people think something must have some validity just because it is published in a non-peer-reviewed publication or offered as a CE event."

The results of the American and Canadian studies seem to indicate that clinicians may not understand the requirements of a science-based analysis of evidence.

"It was troubling to me to see that so many people thought the evidence was there because obviously they're using a different level of evidence than the scientific community is using," he stated.

Perhaps the profession has not moved as close to the science of speech pathology and away from the art of speech pathology as was once thought, he suggested. "I don't ever want to get away from the wonderful art of speech pathology because I think clinicians who exercise their art are very skillful, masterful clinicians who can get a lot out of children. But we not only have to go to the art, we have to go to the science."

One way to move closer to science is to infuse training programs and continuing education offerings with more opportunities to learn scientific methodology for subsequent evidence evaluation.

"Just because people tell you something works doesn't mean that it works," Dr. Lof said. "Just because you observe something doesn't mean that it truly has a causative effect."

As an example, he cited the decade-old controversy over facilitated communication. When looking at the functional speech therapy, "it appeared that the kids were doing marvelously," he said. However, "once it was put to test using scientific rigor, it was shown that the kids weren't progressing; it was the facilitator who was authoring the responses. Just because it looked like the therapy worked, in fact, it did not work."

Clinicians who believe in a particulartheory, including NS-OME, must be willing to put their beliefs to a scientific,evidence-based test.

"This isn't a religion or belief system," Dr. Lof stressed. "This is a scientific endeavor we're doing. If you believe something, you need to test if it's true. You can't just go on faith alone."

Clinicians need to exercise skepticism and demand science-based answers to queries of treatment effectiveness, he urged.

"The people who are selling the products or giving the workshops on non-speech oral-motor exercises often are asking you to believe that they work," he cautioned. "But when you say, 'Where is the evidence?' none is provided and you are expected to just believe them. You can't do that if you're a scientist or a scientific clinician."

Applying critical thinking and the tenets of evidence-based practice to the claims of a particular therapy should be the prime way clinicians evaluate treatment. That mindset exposes the weaknesses ofNS-OME, he said.

For example, NS-OME exercises often are used to teach "mouth awareness" in children. Aside from some phonetic placement cueing, a review of the literature questions the need to teach mouth awareness, Dr. Lof stated. "We don't know at what age kids are mouth aware. Studies show that even 7- and 8-year-olds aren't very aware of the structures within their mouth and their relationship to speech production, so why are we spending all this time on mouth awareness when it's probably not an important variable and not something that kids can take advantage of?"

If the goal of therapy is to change speech, the techniques used should be designed for that purpose, he stressed. "If you want speech to change, work on speech, not on activities that only superficially look like you're working on speech."

A literature review revealed that studies dating back to the 1960s have dissuaded the use of blowing exercises in children with cleft palate, Dr. Lof found.

He also discounted the use of NS-OME for strengthening, explaining that studies have shown only about 10 percent to 15 percent of maximum strength abilities are required for speaking. This alone discounts the need to use strengthening exercises for children with apraxia of speech, he said.

"If they have muscle weakness, they don't have apraxia of speech," he explained. "They have dysarthria, and you've mislabeled the disorder. Kids with apraxia of speech can't have muscle weakness."

A recent research study at Washington State University that compared the tongue muscle strength of children with and without speech sound disorders found that children with speech sound problems had stronger, not weaker, tongues.

"People are doing muscle strengthening for kids with articulation disorders, but they don't have a strength issue!" Dr. Lof said. "We don't need strong articulators; we need agile articulators."

Most oral-motor exercises do not target agility, he noted. Many of the actions in the exercises—such as wagging the tongue, sticking out the tongue, and puckering the lips—do not mimic normal speech actions.

"Why are we doing tasks that have no relevance to the speech sound that we're actually trying to evoke?" he asked. "We don't do those things in these exaggerated ways. People are trying to build agility by using gross movements that have no relevance to the actual production of sounds."

Dr. Lof also questioned the use ofNS-OME for disorders that are not muscle-based or motor problems such as apraxia.

"A phonological impairment is a language disorder," he stated. "Why would kids with a language disorder benefit from a motor approach? The only people who benefit from a motor approach are those who have motor problems. The problem is in diagnosis."

Clinicians are responsible for ensuring that treatment methods are rooted in the proper evidence and remain in line with the principles of best practice.

"It's the clinician's responsibility to read the literature, know where it is coming from, and then evaluate the validity of that literature," Dr. Lof stressed. "I'm always surprised when people ask, 'What literature is showing this, this and this?' You as a clinician should have developed those skills on how to find and evaluate good literature and good evidence. That's our job."

Articles that are not peer-reviewed cannot be used to evaluate validity or determine if a particular therapy works, he noted. "Best practices don't go by hearsay, they go by evidence and theory."

If a movement from within the profession is not enough to push clinicians toward the scientific standards of evidence-based practice, federal mandates will. Laws such as No Child Left Behind and the Individuals with Disabilities Education Act (IDEA) require certain standards of validity in therapy techniques.

"If we don't have the evidence, we need to use good theory," Dr. Lof said. "If you don't do that, you probably aren't following some of the mandates of some of the federal laws to use good practice."

Ideally, university programs should train students in evidence-based practice and critical scientific thought, he said. Both current and future clinicians should embrace a healthy skepticism toward new therapy trends.

"As soon as people stop using non-speech oral-motor exercises to change speech sound production, something else is going to come along," he said. "There's always a fad out there. Some of them may actually prove to work, but you can't just jump on a bandwagon. You need to be able to evaluate the fads."

The debate over NS-OME has spurred ASHA to form the National Center forEvidence-Based Practice Committee. Dr. Lof is a member of the committee, which will evaluate all available data on the topic. One group will focus on the non-speech uses of NS-OME in the areas of feeding and swallowing, and a second group will study speech aspects.

The end result will be a systematic review of the evidence. The committee will present its findings later this year at the ASHA Convention in Boston, MA.

Recalling the overwhelming interest in last year's session, Dr. Lof offered some advice to convention-goers: "Come early."


1. Hodge, M., Salonka, R., Kollias, S. (2005). Use of non-speech oral-motor exercises in children's speech therapy. Poster session presented at the ASHA Annual Convention, San Diego, CA. Nov. 18.

2. Lof, G.L., Watson, M. (In press). A nationwide survey of non-speech oral-motor exercise use: Implications for evidence-based practice. Language, Speech and Hearing Services in the Schools.

3. Rankovic, C.M., Rabinowitz, W.M., Lof, G.L. (1996). Maximum output intensity of the audiokinetron. American Journal of Speech-Language Pathology, 5: 68-72.


  • Finn, P., Bothe, A., Bramlett, R. (2005). Science and pseudoscience in communication disorders: Criteria and application. American Journal of Speech-Language Pathology, 14: 172-88.

  • Jacobson, J., Foxx, R., Mulick, J. (eds.). (2005). Controversial Therapies for Developmental Disabilities: Fad, Fashion and Science in Professional Practice. Mahway, NJ: Lawrence Erlbaum.

  • Lof, G.L. (2006). Logic, theory and evidence against the use of non-speech oral-motor exercises to change speech soundproductions. Invited presentation at the ASHA Annual Convention, Miami, FL. Nov. 17. Hand-out available online at

    For More Information

  • Gregory Lof, PhD, e-mail:

    Alyssa Banotai is an Associate Editor at ADVANCE. She can be reached at


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