Teaching & Learning Guide for: The Study of Variation from Two Perspectives

The study of language variation is fundamental to both sociolinguistics and forensic linguistics (FL). By understanding the similarities between the two fields, sociolinguists can begin to contribute to forensic issues, such as speaker identification. In forensic speaker identification, the linguist determines whether an unknown voice belongs to a known speaker. An example of this would be determining the likelihood that a recorded extortion threat was made by a particular suspect. FL is an applied field which is not only valuable to academia but to society as well. In the United States, many FL tasks are performed by nonlinguists; however, a few sociolinguists have stepped up to the challenge. Sociolinguists are especially well equipped for forensic casework, as they are already familiar with working with real speech and its inherent variation. In this guide, forensic speaker identification is approached by analyzing five types of variation, which sociolinguists are amply familiar with: variation across groups of speakers, variation within speakers, variation between speakers, variation over time, and variation in perception.