I perceive speech easy as a device that only temporarily works. Basically the novelty effect in combination with disrupting 'monitoring/tracking your current stutter voice' and instead focusing on the echo in the device could temporarily gain fluency. According to the research I've read, once the novelty effect wears off or when your body adjusts to the echo of speech easy, then the positive effects (that you once had) are gone and it would have been more effective according to research to do other therapy (e.g., with desensitization elements)