Title of the article

1.2.Categorical nature of intonational contrasts

By intonation or speech melody we mean the pattern of rises and falls in the time-course of the pitch of spoken sentences. Melodic patterns in speech vary systematically across languages, and even within languages across dialects. The cross-linguistic differences can be parameterized and described in much the same way as has been done for the segmentals in language: a set of distinctive features defines an inventory of abstract units, which can be organized in higher-order units subject to wellformedness constraints. Moreover, intonational contrasts are used to perform grammatical functions that can also be expressed by lexico-syntactic means, such as turning statements into questions, and putting constituents in focus. For these reasons it has become widely accepted that intonation is part of the linguistic system (Ladd, 1996: 8). Yet, there have always been adherents of the view that speech melody should be considered as something outside the realm of linguistics proper, i.e., that intonation is a para­linguistic pheno­menon at best, to be treated on a par with the expression of attitudes or emotions. Typically, the communication of emotions (such as anger, fear, joy, surprise) or of attitudes (such as sarcasm) is non-categorical: the speaker shows himself more or less angry, fearful, or sarcastic in a continuous, gradient fashion.

A relatively recent insight, therefore, is that a division should be made in melodic phenomena occurring in speech between linguistic versus paralinguistic contrasts. Obviously, only the former but not the latter type of phenomena should be described by the grammar and explained by linguistic theory. This, however, begs the question how the difference can be made between linguistic and paralinguistic phenomena within the realm of speech melody._³ Ladd & Morton (1997) were the first to suggest that the traditional diagnostic for categorical perception should be applicable to intonational categories in much the same ways as it works for segmental contrasts. Only if a peak in the discrimination function is found for adjacent members on a tone continuum straddling a boundary between tonal categories, are the categories part of the linguistic system, i.e., phonological categories. If no categorical perception of the tone categories can be established, the categories are ‘just’ the extremes of a paralinguistic or phonetic tonal continuum. Ladd & Morton tested the traditional diagnostic on a tone continuum between normal and emphatic accent in English and noted that it failed. This – to me – indicates that the contrast is not part of the phonology of English.

Remijsen & van Heuven (1999, 2003) tested the traditional diagnostic on a tone continuum between ‘L%’ and ‘H%’ in Dutch, and showed that indeed there was a discrimination peak for adjacent members along the continuum straddling the boundary – indicating that the ‘L%’ and ‘H%’ categories are part of the phonology of Dutch. At the same time, however, we had to take recourse to listener-individual normalization of the category boundary, a complication that is not generally needed when dealing with contrasts in the segmental phonology._⁴

Van Heuven & Kirsner (2002) suggested that the relatively weak categorical effects in Remijsen & van Heuven could have been the result of an incorrect subdivision of the ‘L%’ to ‘H%’ tone range. Van Heuven & Kirsner (2002) showed that Dutch listeners were perfectly able to categorize a range of final pitches between low and high in terms of three categories, functionally denoted as command intonation, continuation, and question. However, we did not run the full diagnostic involving both identification and discrimination procedures. Moreover, Van Heuven & Kirsner forced their listeners to choose between three response alternatives, viz. command, conditional and question. Although the extremes of the range, i.e. command versus question are unchallenged categories, it may well be the case that the conditional is not necessarily distinct from the question type. After all, in the grammar developed by ‘t Hart, Collier & Cohen (1990) any type of non-low terminal pitch falls into the same category, indicating non-finality. It occurred to us that we should take the precaution to run the experiment several times, using different response alternatives, such that two separate binary (‘command’ ~ ‘no command’ and ‘question ~ ‘no question’) response sets as well as the ternary response set (‘command’ ~ ‘conditional’ ~ ‘question’) were used by the same set of listeners. If the intermediate ‘conditional’ response category does constitute a clearly defined notion in the listeners’ minds, the binary and ternary divisions of the stimulus range should converge on the category boundaries.

The present paper seeks to remedy the infelicities of Van Heuven & Kirsner (2002). However, before I deal with the experiments, it is necessary to introduce the inventory of the domain-final boundary configurations that can be found in Dutch.