Patent US 5,367,609

A method and apparatus for editing the displayed voice wave form by marking the portion of interest on the screen is disclosed. Marked segment may then be deleted, for example, or copied into another segment in second voice editing window. In either case, pointers are established at the selected marker positions of the displayed voice segment and in the corresponding positions of uncompressed voice segments. The voice data is treated as a stream of fixed-length micro-segments, where there is a predictable correlation between the positions of the compressed and uncompressed data. In the implementation at hand, these micro-segments are 20 ms. in length. Editing is accomplished by modifying micro-segments in both the compressed and uncompressed segments simultaneously. When the user is satisfied with the result, the edited wave form is redrawn on the screen. The user may then SAVE the result, and the entire segment is rewritten to the data base, replacing the previous version. Only the compressed version is written, thus eliminating the need for a subsequent pass through the compression hardware with the associated compounding of distortion.