Also known as: 電動式人工喉頭, 電気式人工喉頭
An electrolarynx, sometimes referred to as a "throat back", is a medical device about the size of a small electric razor used to produce clearer speech by those who have lost their voicebox, usually due to cancer of the larynx. The most common device is a handheld, battery-operated device placed under the mandible which produces vibrations and allow speech.
Source: Wikipedia