An announcement system includes: a sound-pickup apparatus for receiving a speech expressing a fixed-form sentence; a conversion apparatus for generating a translation of the fixed-form sentence based on the speech received; and output apparatus for presenting information indicating the translation. The conversion apparatus includes: a storage unit for storing first-information indicating a predetermined sentence in a mode, and second-information indicating the predetermined sentence in another mode; an audio-input unit for receiving speech-information indicating the fixed-form sentence; speech recognition unit for generating text-information based on the speech-information; conversion processing unit for identifying the first-information corresponding to the fixed-form sentence, based on the text-information and a part of the first-information, before the sound pickup apparatus finishes receiving the speech expressing the whole fixed-form sentence; and transmission unit for transmitting the second-information corresponding to the identified first-information. The output apparatus presents the received second-information by at least either a video or a speech.