Speech rhythm in English and applications to second language teaching

Verbal communication in a second language (L2) involves, among many things, skills in vocabulary, syntax, and pronunciation. Miscommunication can occur due to a slip in any one of these skills. Pronunciation errors in a second language are usually considered to be segmental (consonant and vowel) mispronunciations. A classic example is about Japanese speakers of English confusing /r–l/. For instance, the English driver’s test examiner said ‘‘Turn at the next light’’ and the Japanese person turned at the next ‘‘right,’’ and failed the test. Production and perception of speech sounds in L2 segments (consonants and vowels) are important for successful communication. However, prosody of a foreign language is also extremely important, yet something that has received relatively little attention both in research and second language training. Prosody includes sentence intonation (the changes in fundamental frequency (F0) which constitute the melody of an utterance), and sentence rhythm (changes in the stress, or accent, patterns in an utterance), e.g., [1]. Intonation and rhythm are different, although ‘‘the temporal correlation between intonational and rhythmic cues might actually facilitate the processing of speech rhythm’’ ([2], p. 85). Note that phrasing can often be at the discretion of the speaker, and choices in phrasing affect both sentence rhythm and sentence intonation. In addition, voice quality changes are part of prosody. The term prosody is the catchall term for whatever is not traditionally expressed in the written form of the language. According to some researchers, prosody is at least as important, or more important than accurate segmental pronunciation [3]. Rhythm, as an ingredient of prosody, is also important, and a source of frequent miscommunication. A classic example is the 3-syllable English word, ‘‘McDonald’s,’’ with lexical stress on the second syllable, but spoken by many naive speakers of Japanese as an English loanword, as a 6-syllable word, ‘‘makudonarudo,’’ with a high pitch on the third mora from the end of the word. The position of stress and the number of syllables have changed, thus changing the rhythm; listeners who have no familiarity with Japanese cannot understand the meaning. Minematsu et al. [4], examining transcriptions of sentences by American listeners of foreign accented Japanese English (17,416 responses), reports ‘‘very low intelligibility of Japanese English by Americans with little exposure to Japanese English,’’ p. 1484. A study by Menezes et al. [5] recorded a Japanese bilingual speaker producing 10 true sentences (e.g., ‘‘Autumn is one of the four seasons’’) and 10 false sentences (e.g., ‘‘When it is hot, the sea becomes icy’’), spoken with American English rhythm, and with Japanese English rhythm. The results showed that American college student listeners were able to correctly judge the veracity of the sentences spoken with native-like rhythm better than those with Japanese English rhythm. Rhythmic productions optimize perception by the listener, making speech easier to understand, e.g., [6]. To study the effect on comprehension, only due to wrong rhythm and ignoring segmental mistakes, is difficult for a number of reasons, including the fact that pronunciation of segments is integrally connected with rhythm [7]. Infants use rhythm as a sort of bootstrapping cue toward acquiring their native speech [2,7] around 6 months during the babbling stage [8]. First language rhythm is learned early (perhaps even in utero), learned well and difficult to change later in life.