**To synthesize text** The following ``start-speech-synthesis-task`` example synthesizes the text in ``text_file.txt`` and stores the resulting MP3 file in the specified bucket. :: aws polly start-speech-synthesis-task \ --output-format mp3 \ --output-s3-bucket-name my-s3-bucket \ --text file://text_file.txt \ --voice-id Joanna Output:: { "SynthesisTask": { "TaskId": "70b61c0f-57ce-4715-a247-cae8729dcce9", "TaskStatus": "scheduled", "OutputUri": "https://s3.us-east-2.amazonaws.com/my-s3-bucket/70b61c0f-57ce-4715-a247-cae8729dcce9.mp3", "CreationTime": 1603911042.689, "RequestCharacters": 1311, "OutputFormat": "mp3", "TextType": "text", "VoiceId": "Joanna" } } For more information, see `Creating long audio files `__ in the *Amazon Polly Developer Guide*.