The software application Praat can be used to annotate waveform data (e.g., to mark intervals of interest or to label events). (See <http://www.fon.hum.uva.nl/praat/> for more information about Praat.) These annotations are stored in a Praat TextGrid object, which consists of a number of interval tiers and point tiers. An interval tier consists of sequential (i.e., not overlapping) labeled intervals. A point tier consists of labeled events that have no duration. The 'textgRid' package provides S4 classes, generics, and methods for accessing information that is stored in Praat TextGrid objects.
