The present study examined how the manner of speaking would affect the listener's evaluation of voices. The voices were recorded from four professional voice-over actors spoke 15 sentences in 4 different speaking manners: 1) as if talking to a person, 2) cordially, 3) mechanically, and 4) indifferently. Two different age groups (twenties and forties) of Japanese people rated the voices in terms of likability, credibility, and intentionality (i.e., if it is talking to the listener or not). The result showed that likeability and credibility were highly correlated each other, both ratings were higher in the order of talking to-person, cordially, mechanically, and indifferently. On the other hand, the rating of intentionality showed higher scores with the cordial voices than with voices talking to a person. Furthermore, the middle-aged group showed a higher score in the intentionality rating than the younger group. These results suggest the manner of speaking affects the impression of the voice, which might not always be the way as a speaker intended.