Both SpeechEasy and SmallTalk provide delayed auditory feedback (DAF), which provides the user's voice back to his or her ears a fraction of second later. DAF has been proven effective in dozens of studies.
The SmallTalk also provides frequency-altered auditory feedback (FAF). FAF shifts the pitch of the user's voice up or down in his or her ears. FAF has been proven effective in many studies. It has also been found to induce users to alter their vocal pitch by tensing or relaxing their vocal folds (Elman, 1981; Burnett, 1997, 1998). Stutterers typically use FAF downshifting to induce vocal fold relaxation; in contrast, Parkinson's patients use FAF upshifting to increase speech motor activity.
The SpeechEasy provides frequency-shifting. No study has investigated the effectiveness of frequency-shifting with stuttering. Frequency-shifting can only increase the pitch of a user's voice (minus settings act as high-pass filters and cut off the lower frequencies of users' voices). Hearing one's voice at a higher pitch may increase speech motor activity; no studies have investigated whether this counteracts stuttering therapy that trains relaxed, low speech motor activity speech.
Microphones
Hearing aid microphones pick up sounds around the user, sometimes louder than the user's voice. In contrast, the SmallTalk uses a noise-cancelling directional microphone.
Receivers
The SpeechEasy is monaural (one ear). The SmallTalk can be used either binaurally (two ears) or monaurally (one ear). Binaural (two ear) devices are 25% more effective than monaural (one ear) devices.
SpeechEasy receivers have a frequency range of 200 to 8,000 Hz. In contrast, the SmallTalk uses receivers with a frequency range of 30 to 18,000 Hz. Stuttering therapy focuses on vocal fold vibration or phonation, which is typically 125 Hz in adult males. The SpeechEasy can't reproduce this frequency.
The SpeechEasy has a gain of 10-20 dB with a maximum volume of 105 dB. Background noise amplified to this level can cause hearing damage in minutes.
Effectiveness
Stressful Conversations
Zimmerman (1997) had adult stutterers call New York City businesses using Casa Futura Technologies DAF/FAF telephone devices (a stressful speaking situation) asking scripted questions, without speech therapy; stuttering was reduced 60%. Brenaut (1995) dis a similar study in Halifax and found a 79% reduction in stuttering.
Pollard (2009) had adult stutterers wear SpeechEasy devices for four months. Their speech was tested in three conditions: reading aloud in a speech clinic (low stress); conversation with a researcher (more stress); and asking scripted questions of strangers (high stress), e.g., in a library asking a stranger where the bathroom is. Of the nine subjects who completed the study (one dropped out due to "intolerable background noise"), the devices were more effective for reading aloud (75% less stuttering initially, 58% less during the four month trial, with 27% carryover in the month after discontinuing using the device), less effective in conversations (27%; 15%; 7%), and least effective in asking questions of strangers (2%; 2%). None of these results were statistically significant. 36% of the subjects bought the devices for $1800 (regular price with fees is $4900). No relationship was found between a device's effectiveness for an individual and whether the individual bought the device. 80% (including the subject who dropped out) complained about "irritating background noise" with the device.
Long-Term Effects
Van Borsel (2003) tested nine severe adult stutterers and found that Casa Futura Technologies DAF devices immediately reduced stuttering about 70% in a variety of speaking tasks including conversations. 30 minutes use of the devices per day for three months resulted in 55% carryover fluency, when the subjects spoke without the devices. No statistically significant adaptation or "wearing off" of effectiveness over time was found.
Radford (2005) found that 14 hours use of a Casa Futura Technologies DAF device with therapy reduced stuttering about 50% when speaking without the device, and this carryover fluency was retained for one year.
Stuart (2004, 2006) found that SpeechEasy devices (with brief speech therapy) reduced stuttering about 90% for reading aloud and 67% for monologues. No adaptation ("wearing off") or carryover fluency was seen after four months or twelve months.
O'Donnell (2008) found that in monologues in the speech clinic (low stress) SpeechEasy devices reduced stuttering 89%, and that during telephone conversations with a speech-language pathologist (more stress) over 16 weeks the devices reduced stuttering 58%.
Molt (2009), in an unpublished study of SpeechEasy devices, found a "pattern of initial improvement…followed by gradual relapse…that improvements in fluency scores and on qualitative measures held for the majority of participants after 3 months…but were less pronounced at 6 and 12 months postfitting."
Runyan (2008), in an unpublished study, followed SpeechEasy users over periods ranging from 13 months to 5 years. Some subjects experienced adaptation, but others experienced increased effectiveness over time. Most subjects developed carryover fluency; but a few now stutter more severely than before using the device. "All 10 of the adult participants mentioned environmental noise as a downside of the SpeechEasy."
Background Noise
SpeechEasy users talked about background noise on the SpeechEasy website discussion forum (SpeechEasy, 2003):
"My son…has a very difficult time in school when there is noise or even announcements. He claims he can't hear at all, so he pops [his SpeechEasy] in and out all day long, which makes me anxious about loss and damage and concerned that he'll really get use out of it.…We've toned down the volume and eliminated some of the frequencies.…He has the completely-in-the-canal model which does not permit external volume control."
"…sometimes it is very hard to hear with my SpeechEasy in my ear when there is a lot of noise. It's like having really bad hearing in one ear."
"In meetings or other noisy environments, I miss much of the speech going on. The [SpeechEasy] does have a problem that it decreases you hearing ability by about half and amplifies noise."
"…the feeling of being hard of hearing and living in a world of muffled sounds is driving me crazy!"
"I've gone out to restaurants with my SpeechEasy and the background noise (i.e., other people talking, silverware tapping plates, music) was unbearable to the point where I had to remove the device. In my opinion, the device isn't well suited for social situations where there are a ton of people talking."
In contrast, the SmallTalk's anti-noise features include noise-cancelling directional microphones and a push-to-talk button. Optional accessories include military-grade throat microphones. These features eliminate background noise in even the noisiest environments.
Conclusion
The above studies suggest that SpeechEasy devices are effective for reading aloud and monologues in quiet speech clinics, but less effective in stressful conversations and in noisy environments. Over time, carryover fluency appears to be minimal. Some studies have found that SpeechEasy devices lose effectiveness over time, other studies have not found adaptation. SpeechEasy devices provide a type of AAF that has never been proven to reduce stuttering; microphones that pick up background noise; and receivers that are monaural, incapable of reproducing the full frequency range of human speech, and have a maximum volume with the potential of causing hearing impairment. The devices also lack a telephone interface.
Studies of Casa Futura Technologies devices found that the devices are effective in stressful speaking situations. Over time, the devices train carryover fluency and don't lose effectiveness. The devices provide DAF and FAF; have noise-cancelling microphones; have binaural receivers with full, flat frequency range that don't block hearing; and have a telephone interface. The devices have been tested and certified regarding hearing safety and other factors by Underwriters Laboratories (UL) and ESZ Elektronik-Service GmbH (CE).
References
Acoustical Solutions, "Noise Level Data Tables," http://www.acousticalsolutions.com/education/pdfs/Noise_Level.pdf; and "Noise and Hearing Loss," http://www.asha.org/public/hearing/disorders/noise.htm
Armson, J., Kiefte, M., Mason, J., & De Croos, D. (2006). "The effect of SpeechEasy on stuttering frequency in laboratory conditions." Journal of Fluency Disorders, 31, 137Ð152.
Brenaut, L., Morrison, S., Kalinowski, J., Armson, J., Stuart, A. (1995). "Effect of Altered Auditory Feedback on Stuttering During Telephone Use." Poster session, American Speech-Language Hearing Association convention, from Dalhousie University, Halifax, Nova Scotia, Canada, 1995.
Elman, J. (1981). "Effects of frequency-shifted feedback on the pitch of vocal productions," Journal of the Acoustical Society of America, 70 (1). Burnett, T.A., Senner, J.E., and Larson, C.R. (1997). "Voice F0 responses to pitch-shifted auditory feedback: A preliminary study," J. Voice, 11, 202-211. Burnett, T.A., Freedland, M.B., Larson, C.R., Hain, T.C. (1998). "Voice F0 responses to manipulations in pitch feedback," Journal Acoustical Society of America, 103 (6) June 1998.
Molt, L. (2006). "SpeechEasy AAF device longterm clinical trial: Speech fluency and naturalness measures." Poster presented at the annual convention of the American Speech-Language-Hearing Association, Miami, FL.
National Institute for Occupational Safety and Health, NIOSH Publication No. 98-126: "Criteria for a Recommended Standard: Occupational Noise Exposure," June 1998, Table 1-1 (http://www.cdc.gov/niosh/docs/98-126/chap1.html).
O'Donnell, J., Armson, J., Kiefte, M. "The effectiveness of SpeechEasy during situations of daily living," Journal of Fluency Disorders, Volume 33, Issue 2, Pages 99-119 (June 2008).
Pollard, R., Ellis, J., Finan, D., Ramig, P. "Effects of the SpeechEasy on Objective and Perceived Aspects of Stuttering: A 6-Month, Phase I Clinical Trial in Naturalistic Environments," J Speech, Language, and Hearing Research Vol.52 516-533 April 2009.
Radford, N., Tanguma, J., Gonzalez, M., Nericcio, M.A., Newman, D. "A Case Study of Mediated Learning, Delayed Auditory Feedback, and Motor Repatterning to Reduce Stuttering," Perceptual and Motor Skills, 2005, 101, 63-71.
Ramig, P., Pollard, R., Ellis, J. "Application of the SpeechEasy to Stuttering Treatment; Introduction, Background, and Preliminary Observations," in Treatment of Stuttering: Established and Emerging Interventions, by Barry Guitar and Rebecca McCauley (2009, page 314).
SpeechEasy Discussion Board Forum Index, "Suggestions for my son," May 9, 2003.
SpeechEasy, no date, "General FAQs," questions 2.5 and 2.6, http://www.speecheasy.com/faqs-how.html#25.
Stuart, A., Kalinowski, J., and Rastatter, M. (1997). Effect of monaural and binaural altered auditory feedback on stuttering frequency, Journal of the Acoustical Society of America, 111, 2237-2241.
Stuart, A., Xia, S., Jiang, Y., Jiang, T., Kalinowski, J., Rastatter, M. "Self-contained in-the-ear device to deliver altered auditory feedback: applications for stuttering," Annals of Biomedical Engineering, 31, 233-237, 2003.
Stuart, A., Kalinowski, J., Rastatter, M., Saltuklaroglu, T., Dayalu, V. "Investigations of the impact of altered auditory feedback in-the-ear devices on the speech of people who stutter: initial Þtting and 4-month follow-up," International Journal of Language and Communication Disorders, 2004, 39:1, 93Ð113. Stuart, A., Kalinowski, J., Saltuklaroglu, T., Guntupalli, V. "Investigations of the impact of altered auditory feedback in-the-ear devices on the speech of people who stutter: One-year follow-up," Disability and Rehabilitation, 2006, 1-9.
Van Borsel, J., Reunes, G., Van den Bergh, N. "Delayed auditory feedback in the treatment of stuttering: clients as consumers," International J Language Communication Disorders, 2003, 38:2, 119Ð129.
Zimmerman, S., Kalinowski, J., Stuart, A., Rastatter, M. (1997). "Effect of Altered Auditory Feedback on People Who Stutter During Scripted Telephone Conversations." Journal of Speech, Language, and Hearing Research, Vol. 40, 1130-1134, October 1997.
SpeechEasy is a trademark of the Janus Development group.
"The PFS is a tremendous adjunct to speech therapy and I would recommend it to anyone who wishes to improve their fluency."
"I ordered a DAF machine and saw wonderful results for my students. I used the device to establish fluency and then introduced fluency shaping techniques. I have three elementary students who have "graduated" from the speech therapy program because they no longer stutter! I whole heartedly endorse your products."
"When Jonathan came home on Friday I had him put on the DAF and tell me about his day. IT WAS AMAZING! He did not stutter at all. I have to tell you, I broke down and cried. It was such a joy to hear him talk and not fight to get his words out."
"The SmallTalk really did a miracle job on my stutter, the result was amazing! I can feel it, it teaches me to relax and more calm, this device gives me self confidence! I can talk now to people and answer phones without any fear at all, also last night I attended a party, I was surprised that I can talk already even without using the device."
"I think you should get a Nobel Prize for your work in the SmallTalk. It is a boon to folks like myself who can't say two words without the device, and I thank you with all my heart for your caring."
"In my stuttering group there came a new member with very bad stuttering. When he said his name it took about three minutes with very big stretches in all his body. With the School DAF he almost at once could speak [slowly] with no problem. That is what I every time find with the DAF."
"While wearing the DAF device, the client engaged in conversation with his peer workers, peers eating lunch, and with faculty and staff. There were no disfluencies noted during this observation. Without the use of the DAF device, the client is approximately 80% fluent."
"Thank you, thank you, thank you. It was wonderful to hear Mr. Jonsson's voice on the phone just now, so much immediate improvement although not perfect. He will now start practicing vigorously every day. At this moment he is enjoying conversation with his wife and children. :)"
"I'm full of joy because I tried the device and it worked perfectly. My friends were surprised because I spoke normaly as I never stuttered. You have given me another chance in my life. GOD bless you and your family. Thank you very much."
"I am a speech therapist in the public school system. I have been using the School DAF and had two students graduated from the speech therapy program who now have fluency within normal limits. Thank you for making a great product that is making a difference in the lives of children who stutter.
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"Thank you very much!! The DAF has completely changed my student's life!"
"I have explained the system to a lot of people already including quite a few clients and they are amazed. I am not 100% fluent at all, but even 50% represents a huge improvement. I feel less stressed when in a meeting and can talk much easier. I am experiencing relaxed speech for the first time in my life.
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"The customer who is currently using the DAF says that the unit has profoundly changed his life! (The guy was in tears over the phone when he told me this.)"
"I have been using the device and it has been working great. I am already noticing a dramatic carry over effect."
"The customer who is currently using the DAF with the wires says that the unit has profoundly changed his life! (The guy was in tears over the phone when he told me this.)"
"I no longer have to stutter, I can use the system. I now have choices."
"Every once in a while I will find myself fighting it, trying to over power it by stuttering; but the system takes over and speech flows."
"I am no longer preoccupied with trying not to stutter. What needs to be done becomes the priority rather than not stuttering. "
"My company purchased the Desktop Fluency System last year for me. I have had great success with it. My fluency greatly increased and I also overcame the fears of making and taking business calls. I have also noticed a carry over effect which I believe is partly due to good speech experiences during my day at work."
"Friends who I've not seen in a long time almost always comment on my improved speech. More to the point, I speak more, and in all situations. I always battled my fear of speech. To me, avoiding speech is worse than the actual spasms of stuttering."
"I wanted to relay to you that the Pocket Fluency System has been working well. I have had one Superior Court judge compliment me on my argument, after using your device. It really is a great product, and feel free to use me as a reference."
"Kurt put the headset on and was immediately fluent. I'm sure you've heard this many times before, but we can't tell you how incredulous we were. To hear Kurt fluent for the first time in a long time was quite something for all of us.
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"The PFS works great for me. As a project manager I'm on the phone a lot and on conference calls with ten or more people. The PFS helps me monitor my targets (full breath, gentle onset, etc.) much better than I can on my own. Speaking takes a lot less effort with the PFS."
"I wanted to let you know how pleased I am with the Pocket Fluency System. I gave a 40 minute presentation on some research I did this summer, and it went really well."
"I've been using it for about 3 years. It completely changed my telephone life. I now make business calls, many times a day. Before the DAF, I never made 1 business call."
"I chaired an Alcoholics Anonymous meeting in front of 50 people and was totally fluent with the Pocket Fluency System. The last time I chaired an AA meeting, last Saturday night, I must have stuttered 150 times. I think some of the blocks lasted 4 seconds. Tonight was beyond description!!!! It works!!!!"
"The School DAF device has been very instrumental in fostering fluency with my students. It has been effective with pre-schoolers as well as high schoolers."
"I won a poetry contest. I am a poet and was afraid to read my poetry in public because of my stutter. This was my very first poetry reading. My reading was flawless, and my attention was NOT riveted on my speech. My mind didn't scan ahead, looking for upcoming blocks. I was very relaxed about my speech, having practiced with the DAF at home."
"The improvement in my speech was immediate. With the device I speak fluently most of the time, the device enables me to slow my speech, control my breath, it strengthens my self-confidence and inspires a relaxed feeling. I have to admit, it's a brilliant idea.
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Listeners React to Stuttering An actor who stutters asks audience members what they thought about his speech
Parkinson's Three men with Parkinson's disease and hypokinetic dysarthria, the speech disorder associated with Parkinson's, speak without and then with SmallTalk electronic speech aids.
Carryover Fluency Hillary talks about using her SmallTalk anti-stuttering device to train carryover fluency and no longer need the device.
