The Indiana Speech Project: An Overview of the Development of a Multi-Talker Multi-Dialect Speech Corpus 1

The goal of the Indiana Speech Project (ISP) was to collect a corpus of spoken language samples from a number of different talkers that represent several different regional varieties of American English. Audio recordings were made of five college-aged women from each of six geographic regions of Indiana while they read isolated words, sentences, and a passage and while engaged in a conversation with an experimenter. The residential histories of the women and those of their parents were strictly controlled to ensure that the talkers were good representatives of each dialect region. The Indiana speech corpus will be used for acoustic-phonetic measurements of speech and perceptual studies on regional language variation by different groups of listeners. Introduction and Theoretical Motivation In recent years, researchers in the field of speech perception and spoken language processing have developed a number of speech corpora for conducting acoustic and perceptual experiments on human language. These corpora typically included a number of speakers reading a set of words or sentences [e.g., “Easy-Hard” Word Multi-Talker Speech Database (Torretta, 1995); TIMIT AcousticPhonetic Continuous Speech Corpus (Zue, Seneff, & Glass, 1990); Talker Variability Sentence Database (Karl & Pisoni, 1994)]. Although the talkers often included both males and females, other important indexical variables such as socioeconomic status, age, ethnicity, and regional dialect were rarely, if ever, considered in selecting the talkers. One exception to this rule is the TIMIT Acoustic-Phonetic Continuous Speech Corpus. This corpus contains spoken sentence materials from 630 talkers, representing eight different regional dialects of American English (Zue et al., 1990). While the TIMIT database was originally collected for speech recognition research, it has been used in various acoustic-phonetic studies on the role of gender, age, and dialect in linguistic variation (e.g., Byrd, 1992; Byrd, 1994; Keating, Blankenship, Byrd, Flemming, & Todaka, 1992; Keating, Byrd, Flemming, & Todaka, 1994). While this work was going on in speech perception and speech recognition, sociolinguists have been collecting speech samples from talkers of a variety of ages, socioeconomic statuses, ethnicities, and regional dialects. The emphasis in this research has been on capturing the variability in spoken language as well as collecting extensive demographic information on each talker [e.g., Santa Barbara Corpus of Spoken American English (DuBois, Chafe, Meyer, & Thompson, 2000); CallFriend Telephone Speech Corpus for American English (Linguistic Data Consortium, 1996); TELSUR (Labov, Ash, & Boberg, in press)]. In contrast to the speech stimuli used in speech perception and speech recognition research, these speech samples are typically taken from “natural” language situations such as interviews and telephone calls and less emphasis is placed on obtaining identical utterances from the same set of talkers. While these corpora are useful for many kinds of sociolinguistic research, they are not adequate for perceptual research in which consistent linguistic content across talkers is highly desirable. The initial goal of the Indiana Speech Project (ISP) was to collect a large amount of speech from a number of phonologically distinct dialect regions in the state of Indiana for use in perceptual studies and acoustic analyses. We wanted to combine the best aspects of the speech perception corpora with the unique focus of the sociolinguistic corpora. In particular, our goal was to collect a large corpus of utterances that were consistent across all talkers, allowing for better control of the stimulus materials for a wide range of perceptual and acoustic studies. In addition, we also wanted the talkers in our corpus to be