Learning to recognize unfamiliar voices: the role of language familiarity and music experience

Learning to recognize unfamiliar voices: the role of language familiarity and music experience Micah R. Bregman (mbregman@cogsci.ucsd.edu) Department of Cognitive Science, UC San Diego, 9500 Gilman Dr. M/S 0515 La Jolla, CA 92093 USA Sarah C. Creel (creel@cogsci.ucsd.edu) Department of Cognitive Science, UC San Diego, 9500 Gilman Dr. M/S 0515 La Jolla, CA 92093 USA Abstract neuroimaging results support this perspective, e.g. Belin, Fecteau, & Bedard, 2004), several studies suggest that talker-specific acoustic cues are intertwined with speech recognition. For example, listeners are better able to understand speech from familiar talkers than unfamiliar ones (Nygaard & Pisoni, 1998). While several studies have characterized severe disability in voice identification, few have attempted to investigate differences among individuals’ abilities to recognize voices, although the existence of dramatic individual differences has been noted for many years (Pollack, Pickett, & Sumby, 1954). In clinical cases, voice recognition can be lost completely in individuals with a neuropsychological disorder known as phonagnosia (Van Lancker, Kreiman, & Cummings, 1989). In a pioneering study, Goggin, Thompson, Strube, & Simental (1991) demonstrated that monolingual English speakers were better able to identify the voices of English-German bilinguals when listening to those individuals speak English than when they spoke German. This suggested that, despite many shared acoustic features (both English and German stimuli shared the acoustic features imparted by a particular talker’s vocal tract), the listener’s language background had a strong impact on their ability to recognize the voices. This study suggested that differences in phonological processing that arise from linguistic knowledge are important in voice recognition. Goggin et al. (1991) observed no difference in performance on a voice recognition task for English-Spanish bilinguals when tested on English vs. Spanish speaking voices. They suggested that bilinguals might have equal ability recognizing voices from either language since they have extensive phonological knowledge of both. Bilinguals, however, are heterogeneous in their language background, and it may be the case that late learners, or those dominant in one of their languages do exhibit the voice identification deficits identified in monolinguals. A recent study demonstrated that differences in phonological processing within a language can also affect voice identification. Individuals with dyslexia are significantly impaired in their ability to recognize voices relative to controls, but only in their native language (Perrachione, Del Tufo, & Gabrieli, 2011). This result implies that individual differences in phonological Speech not only transmits semantic information through words and syntax, but also provides cues to a talker’s identity. Differences in a listener’s ability to recognize voices can be attributed to their language background, and in rare cases voice recognition can be selectively damaged in neurological patients. In this study we investigated a group of Korean- English bilinguals and non-Korean speakers’ ability to learn to recognize unfamiliar Korean and English talkers by voice, and to generalize to utterances not heard during training. We observed an interaction between language background and stimulus language for speed of learning, however generalization performance indicated no such interaction when compared to baseline performance. Bilinguals’ performance recognizing English (but not Korean) voices, was predicted by the age they learned English. We also observed that individuals who actively participated in music production exhibited significantly faster task learning than those who did not produce music. This study indicates that language background has a gradient effect on voice learning among bilinguals, and that non-linguistic auditory processing differences, such as music perception, impact voice identification. Keywords: speech perception; music perception; voice; voice identification; individual differences; bilingualism Introduction Speech is generally studied primarily for its ability to communicate semantic meaning from one individual to another. Many complex animal communication systems such as birdsong, however, evolved primarily to communicate more basic information, providing cues that other conspecific listeners use to evaluate fitness and individual identity. Any comprehensive understanding of the evolutionary origins of speech and language will draw both upon the role communication signals play in transmitting semantic meaning, as well as their role in providing cues to identity. Human speech contains many acoustic cues that listeners use to recognize, for example, a talker’s age, gender, emotional state, or even their identity. Collectively, these elements of the speech signal are known as “indexical cues”. Voice recognition, or talker identification, is an important aspect of speech perception, and one that has been relatively little studied. Although often considered separate from the core speech perception system (some