Tao Jiang, MicroDSP Hearing & Speech Lab; Qinxiu Zhang, Chengdu TMC University; Alan Newton, Janus Development Group, Inc., Sonia Malik, SpeechEasy India

Abstract:

This study intends to evaluate an innovative approach to treating stuttering by means of digital hearing technologies. Traditionally, therapies are employed, although some sever stutters have failed to benefit. Delayed auditory feedback (DAF) and frequency altered feedback (FAF) have known to provide effective inhibition to stuttering; thanks to the digital hearing technologies, special therapeutic devices, SpeechEasy, are available as an alternative treatment. The technical modifications and alterations of the device will be discussed in this special application and the survey results of 946 users shared.

Summary:

It is estimated that 3 million people within the US stutter. Despite continuous search for effective treatment, most sever stutters are yet to be helped. Traditional therapies reply heavily on active control of patients’ speech, yet the results are less successful. For years, it has been known that when people who stutter speak the same material in unison with another speaker, they become fluent. This is known as ‘Choral Speech’ which can be created by Delayed Auditory Feedback (DAF), Frequency Altered Feedback (FAF), or a combination of the two.  However, due to the technical restrains, the personal wearable devices built on those principles were not available until the advent of the digital hearing technologies.

The algorithm incorporated with those two features was first created in 2001 and subsequently has been implemented in a hearing aid like device called SpeechEasy from BTE to CIC. The use of this fluency-enhancing device can help people who stutter produce speech that is stable, natural sounding and automatic. This application simply permits patients to hearing his own voice in a manner that is slightly different from the way he normally hears it. DAF allows the user to hear his or her own voice with a slight temporal delay, similar to an echo. FAF allows the user to hear his or her own voice with a shift in the pitch, so the signal heard is either at a slightly higher or slightly lower pitch than the person’s own voice more accessible at any time in any places even without sound treated rooms. The emulation of choral speech has shown noticeable effects.

SpeechEasy comes in three models: BTE, ITC and CIC and may be viewed as an alternative or adjunct to stuttering therapy.  Some users require no further training when using SpeechEasy, and some require minimal training.  People who have learned traditional therapy techniques and employ them when using SpeechEasy report much higher levels of fluency enhancement and more natural sounding speech when using SpeechEasy.

Since 2001, more than 10,000 patients have used SpeechEasy in the world. In 2008, a user satisfaction survey of 5,278 users was carried. Of them, 946 (17.9%) responded and considered as a large and statistically relevant sample size. Of the 946 respondents, over 80% have owned their device for more than 1 year; over 70% indicated that SpeechEasy has made a positive to very positive impact on their life; over 75% are satisfied with their decision to obtain a SpeechEasy device; and nearly 85% of those who use the device would recommend SpeechEasy to others as a treatment option to improve fluency. Of those who responded, 13% rated their fluency as ‘good to excellent’ before receiving  SpeechEasy. With 69% rating their fluency as ‘good to excellent’ after receiving SpeechEasy.

The innovative design of SpeechEasy is a unique application of hearing aid technology to the treatment of speech disorders, thus approving that hearing and speech disorders can be managed by the same technologies.