Part 1
Foundations
1 Prologue: Cross-linguistic and Multilingual Aspects of Speech Sound Disorders in Children
David Ingram
Languages mentioned: Bulgarian, Cantonese, Dutch, English, Estonian, French, German, Greek, Icelandic, Italian, Khoisan language family, Korean, Quiché, Swahili, Swedish, Turkish, Xhosa
The linguist David Crystal once raised the question of whether or not a monolingual English-speaking speech-language pathologist (SLP) would ever need to know something about Swahili. The answer, of course, is a definite yes, no or maybe. Reasons why she should, include the fact that it is interesting to linguists and SLPs, she might move to a Swahili-speaking country one day, she might develop an interest in Swahili folk music and culture or she might have a Swahili-speaking client on her caseload. Reasons why she should not, include she might not like linguistics, never move to a Swahili-speaking country, care for international music or ever see a Swahili-speaking client. That leaves us with maybe.
The field of speech-language pathology has spent over 30 years trying to figure out whether children who have multiple speech errors and poor intelligibility have speech problems or phonological problems. The late Eric Lenneberg (1962) reported a case study of an 8-year-old boy who had acquired English receptively, but could not speak due to severe anarthria (see also Stromswold, 1994). That probably can be described as a speech disorder. Recently, Caroline Bowen (2009) has written a state-of-the-art book on children with multiple speech errors, entitled Childrenâs Speech Sound Disorders. Many of the children discussed in that book sound to me as if they have phonological problems. While Bowen is likely using âspeechâ in the general sense of âspeakingâ, the extent to which phonological problems are exclusively speech based is still an open question, at least for some. The answer to whether or not children have speech or phonological problems then is a definite maybe.
Before we sink into an abyss of indefinity (my word), it should be noted that there are at least two reasons why an SLP should care about languages other than English. One reason is that they are an SLP for clients who speak another language. There are chapters in the present collection that fit into this category. For example, there are discussions of childrenâs speech in numerous languages, including Korean, Icelandic, German and French, among others. The second reason, related to the first, is that they work with clients who are multilingual. Several chapters address this issue as well. SLPs with either of these interests will find this volume of great interest.
What then about the SLP who does not fit either of the above characterizations
Is there any reason for them to take time to learn about multilingual aspects of speech sound disorders
It is to this group that the rest of this chapter is addressed. And hereâs a hint. The study of multilingual aspects of speech disorders provides the greatest evidence available that speech disorders, in many instances, are phonological disorders.
Letâs Talk Greek Dental Fricatives
Letâs talk Greek. I am reminded of a cartoon depicting a university student meeting with his professor of classical languages. The confounded professor responds to the student âitâs supposed to sound Greek to youâ. So, continuing along in the spirit of David Crystalâs comment about Swahili, why should an SLP working with English-speaking children care about Greek
Letâs look at one of the more interesting characteristics of Greek phonology. Greek, like English, has the dental fricatives [Ξ] and [Ă°]. That of itself is interesting because these are relatively rare in the languages of the world (c.f. Ball,
Chapter 5). These two sounds are also among the last sounds acquired in English; for example, they are among Shribergâs late eight sounds acquired (Bleile, 2006; Shriberg, 1993). To understand the nature of these sounds and how they function in English requires an understanding of how they pattern in languages in which they occur.
One possibility that we might consider is that dental fricatives are rare in languages, and that they are rare because they are hard to make. This option is a serious proposal, and has been addressed in linguistics under the general topic of markedness. Sounds that are common in languages, and acquired early, are seen as unmarked or more basic, while those that are rare and later acquired are seen as marked. For purposes of comparison, we can consider the English labiodental fricative [f] as unmarked when compared to dental fricatives. It is relatively common in languages, and is acquired early (cf. Ingram et al., 1980). Also, [f] is a common substitute for [Ξ]. Similarly, [d] is a common consonant across languages, is acquired early and is often a substitute for [ð]. The sound [d] then is unmarked relative to [ð], which would be a marked counterpart.
To a large extent, the above is true, and would lead to certain predictions about Greek. One prediction would be that dental fricatives should show evidence of being marked in Greek relative to unmarked sounds like [f] and [d]. Secondly, we would expect Greek children to acquire these sounds (i.e. dental fricatives) later, and also to use unmarked sounds as substitutes for them. It turns out, however, that these predictions are false. As reported in Ferguson (1978), the following relations hold. (a) The phoneme /ð/ is used in a much wider range of contexts than /d/. It occurs in word-initial position and intervocalically, as well as clusters. It occurs nearly three times more often than /d/, which is mostly restricted to loan words. The fricative therefore can be interpreted as unmarked in relation to the stop, the opposite of normal expectations. (b) The opposite relation exists for /t/ versus /Ξ/. The stop is much more common than the voiceless fricative, resulting in an asymmetry between the voiced and voiceless pairs. (c) Based on the limited data available (see the review in Mennen & Okalidou, 2007; Stephany 1997), dental fricatives are acquired early in Greek, and do not appear to present any undue problems in their acquisition. In fact, a study on Greek children with speech disorders (Petinou, n.d.) found that the children did well with the voiced dental fricative, while having problems with other Greek fricatives (alveolar, palatal and velar, voiced and voiceless pairs).
This ease of production for /Ă°/ is not restricted to Greek children. A colleague of mine followed his sonâs English phonological acquisition, and noted that his sonâs first and only fricative for some time was [Ă°]. All other fricatives were either avoided or replaced with an [h]. This was verified to me while listening to a recording of his son, who I shall refer to as Ian. Ian was very aware of his difficulties with fricatives, and developed a unique means to avoid words he could not say well. Instead of saying them, he would say the word lemon. Here are some excerpts from the recording:
Circumstances such as those just described are an important lesson that phonetic difficulty and articulatory tendencies cannot be taken as absolutes. Children are not just learning how to pronounce. They are learning how to form and store mental representations of words; they are learning a phonological system, not a set of phonological probabilities; and they are learning to approximate the words of the language they are acquiring.
Letâs Talk Turkey (with QuichĂ©)
Topba
(1992, 2007) has extensively studied phonological acquisition in Turkish in both typically developing children and children with phonological disorders. Her data provide opportunities to see what sounds are found to be difficult by both groups of children. A comparison of her studies in Ingram (2008) noted that both groups showed similar phonetic inventories. One striking feature was that both groups acquired affricates relatively early, especially [
]. The affricate [
] also showed a tendency to be acquired before any fricatives. A discrepancy was found, however, regarding [l]. The consonant [l] is not acquired early in English, and is often glided to a [w] or [j]. In the Turkish data, children showed an early glide [j], which presumably would be available for target /l/ phonemes. Surprisingly, the children with phonological disorders showed an early [l], but not the typically developing children. Barring another explanation, we have a case where the children with disorders were apparently doing better on a sound than typical children, relatively speaking.
It turns out that another rather different study found early acquisition of [
] and [l]. Pye
et al. (1987) studied the early consonants of five children acquiring Quiché, a Mayan language spoken in Guatemala. No linguist has ever proposed that Quiché and Turkish are related languages, though unrelated languages certainly can share typological similarities. Pye
et al. found two consonants to be the most frequently used in the early vocabularies of the five children. These were the consonants [l] and [
], the same two sounds noted above for Turkish. Initially, they were stunned by this result, because they had believed, as everyone else at the time believed, that the order of acquisition of speech sounds was determined by phonetic complexity. Wrong. No doubt, phonetic complexity plays a role, but something else was going on.
To explore what else was influencing the early use of [l] and [
], Pye
et al. looked at the distribution of these two consonants in the words that the Quiché children were acquiring. They found a strong correlation between the order of acquisition of the Quiché consonants by children and their use in the vocabulary that they were acquiring. The interpretation was something like this. If a speech sound plays a prominent role in the vocabulary that the child is learning, then that prominence may, at least in the case of Quiché [l] and [
], lead to earlier acquisition than what might be predicted based solely on phonetic complexity. They labeled this influence
functional load, a term that has been used in linguistics for many years (Meyerstein, 1970). Functional load refers to the role that a phoneme plays in the phonological system of a language in terms of how often it contrasts with other phonemes. It needs to be distinguished with phonetic frequency, which is how often a sound occurs in spoken language. This difference can be demonstrated with the English fricative /Ă°/ as it occurs ...