We aimed to construct an ideal speech production substitute for patients with phonation disorder and developed the artificial larynx by using piezo-vibrator as the sound source. To develop this artificial larynx, we investigated the control method using the electromyographic (EMG) signal of human neck muscle. A previous research study confirmed that the EMG signal of the sternohyoideus is effective as the control signal of artificial larynx. The present report describes the application of the EMG signal for pitch frequency control and on/off control of our artificial larynx. The processed EMG signal has a linear relationship with the pitch frequency, and the effectiveness of the EMG signal as the control signal was confirmed. In addition, the prototype control systems by neck EMG signal for welfare applications were developed and evaluated. Furthermore, the application of the EMG signal to the development of other beneficial devices is considered effective, and the new devices are described.