The basis of the manipulations is the estimation of the pitch boundaries. Dependent on the specifications of the user either pitch boundary segments are added or subtracted. This program was created to simulate Hermansky's Acoustical Band Filters which were seen as optimal representations of the speech signal for further processing such as speech recognition. The program generates 16 band filter values for speech frames of a length of about 17 ms. The following images give a snapshot from the speechlab working environment during a labeling session.
Vertical bars indicate the label segments.
Below that window one can identify the labels of the various segments defined in a time-aligned manner. At the left a special window is shown which gives an idea of the user interface of the home-made label tool.