Stuttering Treatment Devices

Number 1.01.518

Effective Date April 24, 2015

Revision Date(s) 04/14/15; 05/12/14; 07/08/13; 07/10/12; 07/12/11; 06/08/10; 04/08/08; 03/13/07; 07/01/06

Replaces N/A


The use of stuttering treatment devices is considered investigational.

Related Policies


Speech Generating and Alternative Communication Devices


Speech Therapy

Policy Guidelines

Altered auditory feedback (AAF) devices to treat individuals who stutter may be used in conjunction with a structured fluency disorder rehabilitation program provided by a speech therapist.

Under some plans speech therapy may not be covered as a treatment for individuals who stutter in the absence of a medical or nervous system disorder. (See Related Policies)

Fluency-enhancing devices (anti-stuttering devices) use AAF and are not covered because they are considered investigational. (e.g. Fluency Master, Pocket Fluency, SpeechEasy®, The Facilitator)




Evaluation of speech fluency (e.g. stuttering, cluttering)

There are no specific CPT codes for devices used to treat stuttering.


Stuttering is a speech disorder that affects the fluency of speech. The disorder is characterized by disruptions in the production of speech sounds, also called "disfluency." This may present as repetitions or prolongations of speech sounds, syllables or words or by an individual’s inability to start a word. Stuttering usually begins in childhood during the time of language development between the ages of two to six. In some cases, stuttering lasts throughout life. About 1 percent or less of adults stutters. Males are three times more likely to stutter than females.


At the present time there is no cure for stuttering. Standard treatment for the disorder involves speech therapy with a variety of therapeutic approaches. Many programs for persistent stuttering focus on relearning how to speak or behavior modification. Treatment often includes educating parents about restructuring the child’s environment to reduce episodes of stuttering. In some cases medications such as haloperidol and risperidone are used. Electronic devices for altered auditory feedback (AAF) have been proposed as a treatment method. The rationale for AAF lies in the observation that individuals who stutter tend to become more fluent when speaking in unison with others, a phenomenon called the choral effect. Delayed auditory feedback (DAF) delays the user’s voice to his or her ears. Frequency-shifted auditory feedback (FAF) alters the pitch of the user’s voice in his or her ears. Masking auditory feedback (MAF) synthesizes a sine wave that imitates vocal fold vibration and pulls the user out of silent blocks. The masking sound is triggered by a laryngeal microphone and played back to the user via an earpiece. The underlying mechanisms that enhance fluency under AAF have not been identified.

Regulatory Status

The U.S. Food and Drug Administration (FDA) categorizes stuttering or anti-stammering devices as Class I devices. As such, these devices are exempt from premarket notification procedures. (1) The FDA defines an anti-stammering device as one that electronically generates a noise when activated or when it senses the user’s speech that is intended to prevent the user from hearing the sounds of his or her own voice. The device is used to minimize a user’s involuntary hesitative or repetitive speech. This techniuqes of manipulating or altering auditory feedback (AAF) is also known as delayed auditory feedback (DAF) and frequency-shifted auditory feedback (FAF).

Trade names for devices used to treat stuttering/stammering include:

  • Basic Fluency System (Casa Futura Technologies, Boulder, CO)
  • Fluency Master (National Medical Equipment Inc., New Hyde Park, NY)
  • Pocket Speech Lab (Casa Futura Technologies, Boulder, CO)
  • SpeechEasy® (Janus Development Group Inc., Greenville, NC),


Medical policies are systematically developed guidelines that serve as a resource for Company staff when determining coverage for specific medical procedures, drugs or devices. Coverage for medical services is subject to the limits and conditions of the member benefit plan. Members and their providers should consult the member benefit booklet or contact a customer service representative to determine whether there are any benefit limitations. This medical policy does not apply to Medicare Advantage.

Benefit Application

Under some plans speech therapy may not be covered as a treatment for individuals who stutter in the absence of a medical or nervous system disorder. Please contact customer service for specific benefit information.


This policy was originally created in 2007. Since that time the policy has been reviewed and updated annually with Medline literature searches. The most recent literature search was through February, 2015. Following is a summary of the key literature.

The published literature on the clinical use and effectiveness of devices developed for the treatment of stuttering consists of a few reports, with extremely small numbers of patients in uncontrolled case series.

Kalinowski et al., in 2004, used a self-report format to assess the efficacy of an ear-level altered auditory feedback (AAF) device used by 105 participants. In each case, the device had been in use for an average of six months with minimal clinical intervention. Participants rated a significant improvement (P<0.001) after beginning to use the device. Based on the data, the authors concluded that the device helped to provide it’s users with functional, effective and efficient management of stuttering without the need for extensive clinical follow-up. (2,3)

In 2008, Stuart and colleagues examined objective and subjective measures of the effect of a self-contained ear-level device delivering altered auditory feedback (AAF) for those who stutter 12 months following initial fitting with and without the device. Nine individuals with developmental stuttering participated. In Experiment 1, the proportion of stuttering was examined during reading and monologue. A self-report inventory inquiring about behavior related to struggle, avoidance and expectancy associated with stuttering was examined in Experiment 2. In Experiment 3, naïve listeners rated the speech naturalness of speech produced by the participants during reading and monologue. The authors found that the proportions of stuttering events were significantly (p < 0.05) reduced at initial fitting and remained so 12 months post follow-up. After using the device for 12 months, self-reported perception of struggle, avoidance and expectancy were significantly (p < 0.05) reduced relative to pre-fitting. Naïve listeners rated the speech samples produced by those who stutter while wearing the device significantly more natural sounding than those produced without the device for both reading and monologue (p < 0.0001). They concluded that these findings support the notion that a device delivering AAF is a viable therapeutic alternative in the treatment of stuttering. However, study limitations included a very small sample size and a nonrandomized design.(4)

In 2009, Pollard and colleagues report on the effects of the SpeechEasy® when used under extraclinical conditions. Their primary purpose was to help establish Phase I level information regarding therapeutic utility of the SpeechEasy®. They also wanted to compare their results with previous findings. Eleven adults who stutter participated. A nonrandomized ABA group was utilized. Speech samples were collected every 2 weeks in extraclinical settings. Qualitative data were collected through weekly written logs and an exit questionnaire was completed. Group analyses revealed a statistically significant effect of the SpeechEasy® immediately post fitting but no treatment effect across 4 months’ time. Individual responses varied greatly with regard to stuttering frequency and subjective impressions. Relatively more stuttering reduction occurred during oral reading than during formulated speech. The authors concluded that Phase II trials were not indicated. (5)

In 2010, Lincoln and colleagues reported on 11 adults who participated in sessions with the study investigator(s) using an altered auditory feedback (AAF) device. Both speech and reading aloud skills were assessed while using the device. The results varied depending on the environmental conditions and device settings of the AAF during the testing sessions for each participant. The study was inconclusive as to the utility of the device for treatment of stuttering due to the inconsistency of the data. No follow up data is available to document the long-term benefit after use of the device has ceased. (6)

Unger, et al. reported in 2012 on their study of the effects of altered auditory feedback (AAF) and one Inactive Condition (AAF parameters set to 0) on clinical attributes of stuttering during scripted and spontaneous speech. Two commercially available AAF devices were used to create the combined delayed auditory feedback (DAF) and frequency altered feedback (FAF) effects. The study participants were adults who stutter (n=30), aged 18-68 years (M=36.5; SD=15.2). Each subject produced four sets of speech samples that were analyzed to detect changes in descriptive features of stuttering (frequency, duration, speech/articulatory rate, core behaviors) and severity of stuttering. A statistically significant difference was found in the frequency of stuttered syllables (%SS) during both Active Device conditions (p=.000) for all speech samples. The most sizable reductions in %SS was in scripted speech. In the analysis of stuttering type, it was found that blocks were reduced significantly (Device A: p=.017; Device B: p=.049). The participants were divided into 2 groups based on the severity of stuttering. During the Inactive Condition those participants in the moderate-severe group (p=.024) showed a statistically significant reduction in overall disfluencies. (7) According to the study authors this result indicates, that active AAF parameters alone may not be the sole cause of a fluency-enhancement when using a technical speech aid.

Ongoing and Unpublished Clinical Trials

A search of the database through February, 2015 identified the following clinical trials:

  • NCT00001602 – Genetic Factors Related to Stuttering a multicenter trial supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health (NIDCD/NIH was completed in February 2005. Objectives of the trial included studying the pathognomony of stuttering, the delineation of subtypes in general with particular reference to persistent and recovered stuttering. The study was designed to increase understanding of the genetic factors related to stuttering, and ultimately to find the etiology. (8) According to the Stuttering Fact Sheet, NIDCD scientists have identified 3 genes that work together to breakdown and recycle cellular components tied to two serious metabolic disorders called mucolipidosis (ML) II and III. Researchers continue studying this finding related to specific problems with speech fluency. (9, 10) The study population was anticipated to be 500 participants but no study results are posted to verify the study results.
  • NCT00001604 – Genetic Linkage Studies of Stuttering is an observational study for the genetic basis for stuttering supported by the NIDCD/NIH. The goal of the study is to find the genes that help cause stuttering and determine regions of the human genetic make-up (genome) that are linked to stuttering. The researchers will study the patterns of inheritance in families who have had members who stutter. The study is currently recruiting for an anticipated enrollment of 4000 individuals.
  • NCT00488657 – Treating Speech Disorders in Patients with Parkinson's Disease Using Altered Auditory Feedback was a Phase I interventional trial using the SpeechEasy Model ITC. The study systematically examined the therapeutic effect of altered auditory feedback provided by the in-the-ear device on the speech impairments in patients with Parkinson's disease. The study included 40 participants and was completed in May 2010. No study results are posted.
  • NCT02094014 – Auditory Masking Effects on Speech Fluency in Aphasia and Apraxia of Speech supported by the NIDCD/NIH is currently recruiting 45 participants for this observational case control study. The primary objective of the research is to test the short-term effects of listening to noise (i.e. auditory feedback masking) on speech fluency in stroke survivors with aphasia and apraxia of speech. The secondary objective is to identify individual factors that predict a positive response, including presence of apraxia of speech, lesion characteristics, and type of aphasia (e.g. Broca's, Wernicke's). The estimated completion date is June, 2015.

Summary of Evidence

Based on a review of the published peer-reviewed scientific literature, there is insufficient evidence to conclude that stuttering devices are effective in the treatment of stuttering or dysfluency. The results of very small, uncontrolled case reports suggest that some individuals experience a decrease in stuttering while using AAF devices. However, well-designed prospective randomized controlled clinical trials are needed to establish the long-term utility of these devices and to define their role in the treatment of stuttering, when compared to standard or no treatment.

U.S. Preventive Services Task Force Recommendations

Not applicable.

Medicare National Coverage

There is no national coverage determination (NCD). In the absence of an NCD, coverage decisions are left to the discretion of local Medicare carriers.


  1. U.S. Food and Drug Administration (FDA). Department of Health and Human Services (DHHS). Subchapter H—Medical Devices. Updated September 1, 2014. Available at URL address: Last accessed March, 2015.
  2. Kalinowski J, Guntupalli VK, Stuart A, et al. Self-reported efficacy of an ear-level prosthetic device that delivers altered auditory feedback for the management of stuttering. Int J Rehabil Res; 2004; 27(2):167-70.
  3. Kalinowski J, Saltuklaroglu T. The road to efficient and effective stuttering management: information for physicians. Curr Med Res Opin. 2004; 20(4):509-15.
  4. Stuart A, Kalinowski J, Saltuklaroglu T, et al. Investigations of the impact of altered auditory feedback in-the-ear devices on the speech of people who stutter: one-year follow-up. Disabil Rehabil. 2006; 28(12):757-65.
  5. Pollard R, Ellis JB, Finan D et al. Effects of the SpeechEasy® on objective and perceived aspects of stuttering: a 6-month, phase I clinical trial in naturalistic environments. J Speech Lang Hear Res. 2009 Apr;52(2): 516-33.
  6. Lincoln M, Packman A, Onslow M, et al. An experimental investigation of the effect of AAF on the conversational speech of adults who stutter. J Speech Lang Hear Res. 2010 Mar 10. [Epub ahead of print] Last accessed March, 2015.
  7. Unger JP, Glück CW, Cholewa J. Immediate effects of AAF devices on the characteristics of stuttering: a clinical analysis. J Fluency Disord. 2012 Jun;37(2):122-34. Last accessed March, 2015.
  8. American Speech-Language-Hearing Association (ASHA). Recent Developments and Future Direction. Stuttering; ©1997-2013. Last accessed March, 2015.
  9. Stuttering Fact Sheet. National Institute on Deafness and Other Communication Disorders. NIDCD. NIH Pub. No. 10-4232. Updated March 2010. Available at URL address: Last accessed March, 2015.
  10. American Speech-Language-Hearing Association (ASHA). ©1997-2013. In Search of Stuttering's Genetic Code Sep 18, 2012. Last accessed March, 2015.
  11. The Stuttering Foundation. (website) © 1991-2015. Electronic devices, software, apps. Last accessed March, 2015.







Durable medical equipment, miscellaneous

Type of Service

Durable Medical Equipment


Place of Service










Add to Durable Medical Equipment Section - New Policy adopted 3/14/06; held for notification—effective 07/01/06


Replace Policy - Policy updated with literature review; no change in policy statement.


Replace Policy - Policy update with literature search; no change to the policy statement. Reference added.


Code Update and Cross Reference Update - E1399 added; no other changes.


Replace Policy - Policy updated with literature review, no change to the policy statement. Reference added.


Replace Policy - Policy updated with literature search; no change to the policy statement. Reference added.


Replace Policy - Policy updated with literature search; no change to the policy statement.


Replace policy. Policy updated with literature search. ICD-9 codes added 315.35, 438.14, 784.52.The policy statement is unchanged.


Replace policy. Clarification statements about speech therapy added to policy guidelines. Regulatory information moved to new section under Description. Rationale section reformatted for usability. References renumbered to match rationale format. References older than 5-years that were not cited are removed. ICD-10 diagnosis codes added. Policy statement unchanged.


Annual Review. A review of the literature through March 2014 did not prompt changes to the policy statement or rationale sections. No new references added. Policy statement unchanged.


Annual Review. Revised the title of policy 1.01.502 in the Related Policies section. Policy updated with a literature review through February 2015; reference 7 added. Three clinical trials added. Policy statement unchanged. Remove ICD-9 and ICD-10 codes removed; these are not utilized in policy adjudication.

Disclaimer: This medical policy is a guide in evaluating the medical necessity of a particular service or treatment. The Company adopts policies after careful review of published peer-reviewed scientific literature, national guidelines and local standards of practice. Since medical technology is constantly changing, the Company reserves the right to review and update policies as appropriate. Member contracts differ in their benefits. Always consult the member benefit booklet or contact a member service representative to determine coverage for a specific medical service or supply. CPT codes, descriptions and materials are copyrighted by the American Medical Association (AMA).
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