Project Summary

Project Title: Vowel Overlap Indication Software (VOIS3D) Project

Funding: University of Washington, RRF Grant 65-2597, Proposal #2952

Budget Period: 2/1/03 to 1/31/04

Principle Investigator: Alicia Beckford Wassink, Department of Linguistics

Submitted: 6 May, 2004

Scope of Work

This project involved the development of computer software for use by researchers in several subfields of linguistics, including sociolinguistics, phonology, and phonetics. The project had three phases: first, modification of the preexisting computer program (Wassink, 1999) that provided an analytic geometric solution for assessment of spectral overlap (Spectral Overlap Assessment Metric) for two spectral dimensions (F1, F2). The initial modification involved provision of a graphical user interface and extension of the program's functionality to assess overlap in either two or three dimensions; second, construction of three sets of appropriate linguistic data for the purpose of testing and demonstrating application of the software to topics of theoretical interest. Finally, the proposed research was to culminate in the submission of a scholarly article for publication (Wassink, 2006). The specific outcomes of this RRF-funded project are the extension of the user interface and development of a set of test data. These are described below.

Extension of User Interface

One major undertaking of the project was to find a suitable programming environment to use in extending the existing program (written in MATLAB 4.2c.1). A number of programming environments were considered and tested, including .NET, Flash, Visual Studio C++, C-sharp, and Open GL. In the end, it was possible to extend the user interface and accomplish necessary programming work using MATLAB 6.5.1 software. This was quite advantageous because it did not require rewriting the core code for the overlap algorithm. MATLAB 6.5.1 offers advanced graphical tools such as user input dialogue boxes, buttons, object handles, etc. that greatly improve the accessibility and usability of the program (i.e., the user need not type in line-level commands). It is cross-platform compilable (for use on Macs and PCs). In addition, this newest version of MATLAB enables the target data to be read into the program from several types of files (tab-delimited text, comma-delimited text, Microsoft Excel databases), or directly input to the program. This further simplifies the user's tasks. He or she may select among external data files using a menubar, rather than having to type the name of the source files into the VOIS3D code itself, as was required in the previous version of the program. Fig. 1 shows the new interface and a sample output window.

An unexpected bit of functionality incorporated at no additional cost (but which had not been planned in the project proposal) is that the new VOIS3Dprogram is able to normalize spectral and durational data using several different algorithms already used in the discipline (e.g., Lobanov, 1971; Nearey, 1977; Shirai, 2004). Previously, the software required that data be normalized before use of the program. However, it became evident that end-users might utilize VOIS3Dto compare overlap among different types of acoustic data, e.g. within- or between-speaker comparisons, or within-speaker comparisons of time series or other paired data. A means was devised whereby the program automatically checks the composition of the user's database and finds possible grouping variables along which the user may partition their data. The VOIS3D manual informs the user of the normalization procedures available in VOIS3Dand data types most appropriate for each, and the user chooses a method for normalization from a pulldown menu. All eligible methods may then be executed, and their results subjected to side-by-side comparison in a results field on the main screen. The user can also specify when the data to be checked for overlap were already normalized before being imported into VOIS3D.