To solve the problem that there are two systems for a button indicating start of voice input, that is, a push while talk(PWT) system in which talk is made while keeping pushing, and a push to talk (PTT) system in which talk is made by pushing and then releasing a button, and a user may incorrectly use it without understanding which system can be used.
Incorrect use is judged by detecting a button pushing period and user's utterance existence, and correct usage is guided. In the PWT system, it is judged that it is misunderstood as the PTT system, when the button pushing period is short and after that, the user utters. In the PTT system, when the button pusing period is long, and the user utters within the period, it is judged that it is misunderstood as the system in which talk is made while keeping pushing.
HIROTA MAKOTO
NAKAGAWA KENICHIRO
Yuichi Uchio