June 11, 2013

Blogging about Research

Once a month SLP Bloggers are blogging about research related to the field of speech pathology. You can learn more here.
"Oh no! Not another /r/ referral!" (source)

This month I selected a research article about using biofeedback during intervention for /r/. Most speech-language pathologists I talk to will probably say /r/ is the most challenging speech sound to train. So any new treatment approaches should be welcomed with open arms, right? Let's find out.


"Uh oh, I just know she's going to make
me work on /r/ again today!"

The authors of this study aimed to investigate a treatment approach using biofeedback for persistent /r/ speech sound errors. These are the children who don't make much progress, if any, as a result of traditional therapy approaches. They quote other research articles (which I'm now also interested in reading) which discuss the ethical considerations of discharging patients with residual/persistent speech sound errors from therapy vs. keeping them on the caseload when showing little to no progress.

Because the tongue formation of /r/ is not easily visible, the researchers used visual biofeedback in the form of a real-time LPC spectrum of speech sounds. Now children could see a visual representation of their speech compared to a visual model of a correctly articulated /r/, allowing modification of his/her productions to try and match the models.

A total of 11 children with treatment-resistant /r/ errors were chosen for this research study. They ranged in age from 6 years 0 months to 11 years 0 months; 10 males and 1 female; previous traditional treatment ranging from 0-4 years.

There were two phases to the research: Phase 1: All participants received a standardized program (moving from isolation, to syllables, to words) of traditional treatment last 4, 5, or 6 weeks. This treatment phases was intended to overcome differences from previous instruction the children had received. Phase 2: Immediately after the traditional treatment period ended, participants entered a similarly structured period of visual acoustic biofeedback. Participants were trained with vowels to match their speech productions to the templates on screen. When they were able to show success, they moved on to /r/ productions. Participants were cued to modify productions using cues learned during treatment Phase 1, resulting in a hybrid of traditional and biofeedback therapy. Word list probes were administered prior to treatment, following traditional treatment phase, and following biofeedback treatment phase.

Progress was monitored based on the perceptual accuracy of the /r/ probe lists, the acoustic measurement of the /r/ probe lists, and the perceptual accuracy of /r/ in isolation and /r/ + vowel during treatment.

A variety of mixed results were found:
1) /r/ sounds produced in cluster contexts were significantly more likely to be perceptually rated correct by clinicians than /r/ in other contexts. Vocalic /r/ sounds were also more likely to be rated correct than consonantal /r/ sounds. This could all be the result of the duration of these /r/ sounds - shorter duration = less time to pick up on erroneous productions.

2) Acoustically, the mean F3 formant following the biofeedback treatment phase was lower, indicating the /r/ productions following biofeedback were more acoustically correct than before treatment.

3) As a group, there were no significant changes noted in accuracy of /r/ productions following the traditional treatment period, but gains were observed following biofeedback treatment period.

4) BUT, only two participants showed a significant degree of generalization to /r/ in untreated words - i.e. there wasn't a whole lot of carryover! However, the significant changes noted immediately during and following biofeedback treatment show that this treatment method may be most effective in the earliest stages of intervention when students are acquiring their target sound, and then proficient productions of the target sounds can be mastered through traditional treatment or motor learning approaches.

My Thoughts:
*I'm a big fan of the idea of children "seeing" the results of their articulatory placements. With biofeedback they can visually see the effects of moving their tongue around or rounding their lips. This may be especially great for those students who aren't perceptually accurate at rating their own sound productions as correct/incorrect.

*Initial cost to integrate this technology into practice would be too high. Is it really feasible for schools/clinics/private practices to acquire the equipment necessary to use biofeedback? Would it be applicable to enough students to make the cost worth it? Would clinicians be willing to be trained to use the equipment? I know of some clinics near where I live that are using VisiPitch in their practice to target /r/ treatment. The Voice Analyzer Pro app is an example of much less expensive spectrum/spectrogram software that would be more reasonable for everyday use. However, I'm not familiar with how accurate or easy to use it is.

*This study was limited to participants who showed only /r/ errors and had not responded to previous intervention. I would be interested in seeing if faster progress could be made for children who are responding to traditional treatment approaches. If that's the case, we could get them back into the classroom sooner. Also, I would love to see follow-up studies targeting other speech sounds (e.g. /s/, /l/, /sh/)

*The lack of carryover and generalization makes sense. It's not like the equipment could be sent home with participants so they could practice in other settings and with other communication partners (e.g. parents, teachers, neighbors, etc.) Perhaps a longer-term study would show treatment effects generalize to other settings and other people. Also remember, though, that not all children respond to traditional and empirically sound treatment approaches at the same rate in the real word either.

*The study had mixed results when looking at age as a predictor of progress using biofeedback intervention. More research definitely needs to be done in this area. It may depend on the individual, but do children younger than 6 years old have the cognitive-linguistic skills necessary to understand and respond to biofeedback?

*The authors also noted this wasn't a true biofeedback approach due to the use of articulatory cues during the biofeedback phase that were trained during the traditional treatment phase. This is an understandable complication from a scientific standpoint, but in the real world, most students are likely to receive more than one treatment approach or a hybrid of elements from various approaches anyway. Personally, as long as improvements are made, I'm not too concerned about following standardized treatment protocols to a T.

How I Will Transfer To My Practice:
In this research study, children showed different results with the vocalic /r/ vs. consonantal /r/ and /r/ in cluster contexts. This will be great to keep in mind when working with my students. I need to find a context they are successful with and use that success to shape their treatment.

I would love to use some form of visual feedback for my students. Particularly those who I'm running out of "tricks" to use! Even video self-modeling has been shown to be effective in articulation therapy. If I can capture video of them successfully using their target sounds, I can show them being successful! How powerful for students to see!

I would also definitely be interested in applying biofeedback therapy to the treatment of other sound errors as well. In my opinion, /sh/ and /ch/ affricates are such tricksters to train - maybe biofeedback could result in a breakthrough!

What do you think? Did this research intrigue you? Get you thinking about how to incorporate into your own practice? What research topics would you like to read about in the coming months?

McAllister Byan, T, & Hitchcock, Elaine R. (2012). Investigating the Use of Traditional and Spectral Biofeedback Approaches to Intervention for /r/ Misarticulation. American Journal of Speech-Language Pathology, 21, 207-221.

Whew! I've been a bit out of practice reading research articles since finishing graduate school. I'm so excited to challenge myself and dive into current research again. Head over to Talks Just Fine to see all the other participants and read their research reviews.


  1. Great review! I agree, it would be interesting to see if biofeedback quickened progress in the artic population overall. Also, love the idea of video recording R attempts. Would visual and sound effects like in Google Hangout be good for this population? You can add dog ears, hats, mustaches, etc. to faces on the video screen. You could rename the items to hit your target sounds.

    1. Right, this study looked only at those kiddos who hadn't responded to traditional treatment. It would be so interesting to see how much faster students who are responding to therapy could progress with biofeedback. Sometimes students are making great progress, but just need that little extra "boost" to really take off.

      I haven't upgraded my Google chat to Google Hangout yet - it sounds fun! Thanks for reading, and thanks for organizing the research blogging!


  2. What a great review! I agree; anything that builds a feeling of success is a worthwhile tool. And with the positive effects both seen and potential (generalizing with extended therapy), I can only see this as a positive. While you did mention the cost prohibitive nature of such therapy, I wouldn't be surprised to see an app in the near future which utilizes this technology. I look forward to it. I also look forward to, now, knowing what to look for. Thank you.


    1. Thanks for reading Rowan! I too am excited about finding an app to help me (more affordably) integrate this technique into therapy. I'm a little disappointed I have to wait until school starts again in the Fall to try this! Are you working over the summer?