Issues in the Transcription of English Conversational Grunts

Conversational grunts, such as uhhuh, un-hn, rnrn, and oh are ubiquitous in spoken English, but no satisfactory scheme for transcribing these items exists. This paper describes previous approaches, presents some facts about the phonetics of grunts, proposes a transcription scheme, and evaluates its accuracy. 1 1 T h e I m p o r t a n c e o f C o n v e r s a t i o n a l G r u n t s :Conversational grunts, such as uh-huh, un-hn~ ram, and oh are ubiquitous in spoken English. In our conversation data, these grunts occur an average of once every 5 seconds in American English conversation. In a sample of 79 conversations from a larger corpus, Switchboard, urn was the 6th most frequent item (after /, and, the, you, and a), and the four items uh, uh-huh, um and urn-hum accounted for 4% of the total. These sounds are not only frequent, they are important in language use. To mention just one example, people learning English as a second language are handicapped in informal interactions if they cannot produce and recognize these sounds. 1I would like to tb.nlr Takeki Kamiyama for phonetic label cross-checld-g, all those who let me record their conversations, and the anonymous referees; and also the Japanese 1Vr;nlqtry of Education, the Sound Technology Promotion Foundation, the Nakayama Foundation, the Inamori Foundation, the International Communications Fonndation and the Okawa Foundation for support. Just to be clear about definitions, in this paper 'grunts 2' means sounds which are ~not words', where a prototypical "word" is a sound having 1. a clear meaning, 2. the ability to participate in syntactic constructions, and 3. a phonotactically normal pronunciation. For example, uh-huh is a grunt since it has no referential meaning, has no syntactic affinities, and has salient breathiness. In this paper 'conversational' refers to sounds which occur in conversation and are at least in part directed at the interlocutor, rather than being purely self-directed 3. Both of these definitions have flaws, but they provide a fairly objective criterion for delimiting the set of items which any transcription scheme should be able to handle. The phenomena circumscribed by this definition are a subset of "vocal segregates" (Trager, 1958) and of "interjections": the difference is that it limits attention to sounds occurring in conversations. This definition also roughly delimits the subset of "discourse markers" or "discourse particles" which occur in informal spoken discourse. As the phonetics and meanings of conversational grunts are currently not well understood, we have begun a project aiming to elucidate, model, and eventually exploit them. The current paper is a report on an approach 2 It may seem that the negative connotations of the word 'grunt ' maire it inappropriate for use as a technical term, but the phenomenon itself is often stlgmatised, and so the term is appropriate in that sense too. STwo rules of thnmh were adopted to help in cases which were difllcult to judge: consider laughter as not conversational, and consider as conversational everything else that might possibly be playing some communicative role, even if it isn't clear what that role might be.