Abstract: Selecting human speech samples for a speech model of human speech is preformed. The system presents a graphic representing a human speech sample on a computer display, e.g., an amplitude vs. time graph of the speech sample. Through user input, the system marks a segment of the graphic. The marked segment of the graphic represents a portion of the human speech sample. The system plays the portion of the human speech sample represented by the marked segment back to the user to allow the user to determine its acceptability for inclusion in the speech model. If so indicated by the user, the portion of the human speech sample represented by the marked segment is selected for inclusion in the speech model. The system also analyzes the portion of the human speech sample represented by the marked segment for acoustic properties. These properties are presented to the user in a graphic of the analyzed portion representative of the acoustic properties, e.g.