1. The elderly in China may need to consult a dictionary for pinyin input, and may have trouble writing words on a device. But they need to communicate with their busy children through text. 2. People with expression disorder may deny themselves as they cannot express themselves well and feel not being understood. They may even suffer from mental disease in this case; 3. The deaf-mute are often ridiculed and feel not being understood, commonly vulnerable to the feeling of inferiority and helplessness. 4. In the post-pandemic period, COVID-19 still severely endangers our life. Some people may demand touchless input to avoid disease spreading.