President Obama's public speeches and private dialogues were phonetically analyzed. Prominence, both in speeches and in dialogues, depended on pitch change most, pitch second, and sound pressure third. In the speeches, non-falling tones were used at the end of more than 1/3 of the tone groups and the percentage of non-falling tones at nuclei was around 40%. The speeches consisted of 60–70% speech and 40–30% pause. Although little difference was noticed in the frequency of pause appearance between the speeches and the dialogues, the average length of pause was more than 2.3 times in the speeches. The slow-down in the speeches was not caused by the rate of articulation but by the longer pauses. For emphasis, there were the rate reduction at the tone group to emphasize, or the sound lengthening at the item just before the emphasized tone group with the greatest rate, and conversely the rate elevation at the tone group preceding it.