Note: The following paper was written as the final project for LING 470: Children's Speech, instructed by Professor William O'Grady and assisted by Michiko Nakamura, at the University of Hawaii at Manoa.

The Phonemic Inventory of an American-English/ Japanese
Bilingual one-year-old Child During the Babbling Stage

INTRODUCTION

As my final project for Linguistics 470: Children’s Speech, I will take a close look at the phonemic inventory of an American-English/ Japanese bilingual one-year-old child during the babbling stage. Studies have shown that monolingual children the world over tend to produce similar sounds during the babbling stage. Although these are strict tendencies, researchers have found that some sounds are very common among developing children while others are quite uncommon. Two languages that appear to have similar sounds among babbling children are English and Japanese (O’Grady, 2000: 110-1). In light of these similarities, it seems interesting to examine the phonemic inventory of a child who is simultaneously bilingual in these two languages and look at issues applicable to this research.

Within the vast literature of child language acquisition, there is surprisingly little research about simultaneous bilingualism. A simultaneous bilingual is defined as a child who is exposed to and acquires two languages from birth (Baker, 1996). Given the complexity of the issues associated with language research of monolingual children, it is understandable to find a shortage of simultaneous-bilingual research in child language-acquisition literature. In view of this, for my research project I will combine information gathered from simultaneous-bilingual research with relevant issues from monolingual child language-acquisition research to form a coherent article containing specific issues pertinent to my topic.

Though this project, I will test my hypothesis that an American-English/ Japanese bilingual one-year-old child during the babbling stage will have the same phonemic inventory as both American-English and Japanese children at the same stage of linguistic development. My prediction is that the phonemic inventory of the simultaneous-bilingual child will be an exact combination of American-English and Japanese phonemes found in monolingual children of the same age. The following two questions will be guiding my study during this final project:

1) What is the phonemic inventory of an American-English/ Japanese bilingual child during the babbling stage?
2) Is this child’s phonemic inventory comparable to both American-English and Japanese normally developing children of the same age? If not, are there phonemes lacking or extra?

I will begin my study with a literature review of various issues related to my specific topic. Then I will talk about the naturalistic research that I conducted in order to determine the phonemic inventory of my subject. Lastly, I will analyze the data found in my research and conclude with some discussion of my findings.

LITERATURE REVIEW

At the onset of this final project, I had decided to begin my research by looking at Japanese/ English bilingual studies and comparisons of Japanese and English phonemes. However, throughout this semester I was surprised to find very little research on either of these topics that would be relevant to this paper. I was able to find only one article examining Japanese/ English bilingual children (McCreary, 1988), but the subjects of this article were several years older than my subject, making the study useless to my project. I also was able to locate only one comparison of Japanese and English phonemes. This came from a study by Nakazima (1972), and although he dealt with babbling, he was mainly concerned with the beginning of the phonemicization process which occurs around age 1; 6. This article was able to supply me with a Japanese child’s vowel phonemes.

Having found very little information to begin with, I turned my attention to babbling where I found a few working definitions that I will use throughout this paper. First of all, there are several levels of babbling in infants. Prevocalized babbling is seen as almost uncontrolled production of meaningless sounds. This is found in infants under 6 to 9 months old. The next step, canonical babbling, usually occurs from as early as 6 months old up to 12 to 15 months old. Canonical babbling is characterized by “controlled, repetitive production of well-formed syllables” (Oller et al. 1997) and is the type of babbling referred to throughout this paper. The last step of babbling is called prelinguistic babbling and it begins about the time that the first words are regularly produced and can continue for several years (Oller et al. 1997).

Quite a great deal of research regarding babbling has to do with the connection between the phonemic inventory during the early babbling stages and the phonemic inventory of the linguistic environment. Several researchers support this hypothesis with studies and data that connect babbling with the target language (see de Boysson-Bardies and Vihman 1991, and Blake de Boysson-Bardies, 1992.) On the other hand, some researchers claim that there is no clear connection between babbling and later adult-like speech production (Locke, 1993.) This issue is relevant to my study because I will look for phonemes that I hope will be a part of Hannah’s productive phonemic inventory. If there were no connection between babbling and the L1, then a study of the phonemic inventory of a babbling child would be unnecessary in the long run.

The following table gives the consonant inventory of an American-English one-year-old child. The chart is adapted from one used by Dobrovolsky (1997) to show consonant phonemes of English. The phonemes presented in this chart are found in research conducted by Leyitt and Aydelott-Utman (1992) on the connection between babbling and early speech production. The consonants shown here represent the inventory of just one child and are provided for reference.

Table 1: Consonant Inventory of an American-English one-year-old Child

The following table gives the consonant inventory of a Japanese one-year-old child. The chart is also adapted from Dobrovolsky (1997). The phonemes presented in this chart are found in research conducted by Nakazima et al. (1988) on a comparison of the articulatory development of normal infants and infants with cleft palate. The consonants shown here also represent the inventory of just one normally developing child and are provided for reference.

Table 2: Consonant Inventory of a Japanese one-year-old Child

The following two tables show the vowel inventories of an English (Table 3) and a Japanese (Table 4) one-year-old child. The vowel charts are adapted from charts used by Ladefoged (2001) to visually depict vowel formants in the oral cavity. The American-English vowels presented here are also from the babbling and early speech research conducted by Leyitt and Aydelott-Utman (1992). The Japanese vowels are from another study by Nakazima (1972) on a comparison of the speech development of Japanese and American children. Each chart represents the vowel phonemes of one child from each language and is provided for reference.

It should be noted that both of the previous sets of consonant and vowel phoneme charts represent the phonemic inventories of just one child from each of the two language groups. Although one child cannot possibly represent an entire language group, the charts will be used as target references to compare with the data found in this project. I would also like to point out that it was somewhat difficult to find studies listing the typical phonemes of American-English and Japanese one-year-old children. I had originally thought that this was going to be relatively easy, but after a great deal of literature research, I was able to find only three good sources of compete phonemic inventories. Several researchers of child language (de Boysson-Bardies and Vihman, 1991), (O’Grady, 2000), and (Vihman, 1993) refer to common phonemes and frequencies of certain phonemes found among babbling children the world over without going into detail of the complete phonemic inventories. This possibly could be due to the extreme individual variation found among babbling children and across language groups (de Boysson-Bardies et al., 1992).

SUBJECT

The subject of this research project is my daughter Hannah. She has been raised as a simultaneous bilingual from birth. She is half-Japanese on the maternal side and half-English on the paternal side. Hannah spends approximately 15% of her waking hours with her father only, 30% of her waking hours with her mother only, and 55% of her waking hours with both parents. She receives most of her English input from her father and most of her Japanese input from her mother. However, she also gets limited English input from her mother and limited Japanese input from her father. In addition, some of her input of the two languages is in the form of code switching and language mixing. Code switching is when a person consciously alternates between two or more languages, usually for specific purposes and in specific situations (Baker, 1996). Language mixing is a phenomenon that occurs when people constantly mix their languages unconsciously, for no specific purpose, and in no specific situation (Baker, 1996). Consequently, Hannah’s parents do not follow the one-parent, one-language strategy of simultaneous bilingualism advocated by several leading researchers in the field of childhood bilingualism (Arnberg, 1987).

METHOD

This research project was conducted over a 15-day period from one week before her first birthday until one week after her first birthday. Originally I had intended to observe her in 30-minute sessions at home and at the same time each day. However, this quickly became too restrictive, and I changed this requirement to at least one hour per day in two different sessions in a home-like setting. Part of the reason for this change was a family vacation to Japan taken during the research period. Another reason for this change was the unpredictable nature of a one-year-old. Sleep, feeding, and activity schedules varied considerably from day-to-day, making a set observation time too limiting.

During the observation sessions, I intently examined and logged the spontaneous sounds that she made either on her own or with prompting. I tried carefully to make note of sounds that were part of her babbling repertoire and not other common infant vocalizations such as squealing, growling, and isolated vowel-like sounds, thereby following the criteria set by Oller et al. (1997) regarding canonical babbling research. On seven of the 15 days, some of the sessions were tape-recorded for closer examination and transcription. The recordings were made with a hand-held Radio Shack tape recorder. After each observation session, I reviewed the notes taken and added comments and additional observations. In addition to the formal sessions, I noted other strange and unique observations heard throughout the course of the day.

DATA

After conducting all of the observation sessions with Hannah, I gathered together all of the data for analysis. I reformatted and rewrote each of the log entries of the observation sessions so that they would be easier to study. Each log entry can be found in Appendix I. Furthermore, I transcribed parts of three tape-recorded sessions for additional analysis and to provide examples of typical utterances produced during the observation sessions. These transcriptions can be found in Appendix II.
Afterwards, I made separate charts for Hannah’s consonants and vowels to facilitate their comparison with the phonemic inventories of monolingual American-English and Japanese children. These charts can be found in the tables below. The chart in Table 5, including phoneme locations, is a modified version of the chart found in Dobrovolsky (1997: 32). The chart in Table 6, including its phoneme positions, is taken from Ladefoged (2001:74).

The following table shows the consonant phonemes produced by Hannah at one year, one week old (1; 0, 1):

Table 5: Hannah’s Consonant Phonemes

The following table gives the vowel phonemes produced by Hannah at one year, one week old (1; 0, 1):

Table 6: Hannah’s Vowel Phonemes

It should be pointed out that during this project from the beginning of the observation sessions until the data was organized and ready for analysis, I have tried to be as correct as possible given my limited knowledge of child language acquisition and linguistics. At times during the observation sessions and while reviewing the tape recordings, I had to make decisions about some utterances. It is entirely possible that some phonemes were overlooked while others were mistaken. I have realized through this research some of the difficulties associated with the study of pre-linguistic children. Some utterances are completely unintelligible, sometimes it is hard to distinguish babbling from non-speech sounds, and at times young children can be very unpredictable. However, I have made every effort to avoid errors in my observations and transcriptions in order to provide an accurate analysis of the data.

ANALYSIS

To analyze the data gathered throughout this final project in a coherent manner, I have organized the relevant parts into the following categories: consonants, vowels, and clusters. Due to space and time limitations, I will focus on some of the more interesting observations in each category and attempt to provide explanations and insight where possible.
Regarding consonants the most interesting finding involves the voiceless fricatives /ƒ/ and /x/. In almost every observance of these phonemes, they occurred in isolation only. Hannah usually uttered these sounds when pointing at an object or directing her attention at something. This is very puzzling, and I have no explanation for it.

Another interesting aspect of Hannah’s consonants has to do with the ones that she has that the reference groups lack. I observed the uvulars /q/ and /G/ on nearly every day during the observation period. Hannah used these phonemes in isolation and in combinations with other phonemes. On the last two days of the observation period, she began articulating /q/ very clearly within combinations of sounds. She uttered /ts/ consistently throughout the observation period. This is interesting because it is a phoneme of Japanese (Akamatsu, 1997) yet it was not a phoneme observed in the inventory of the Japanese reference.

Among the consonants that Hannah did not utter that are found in the referent groups, the most interesting are found in the palatal region. /c/, /Ô/, and /µ/ are all Japanese phonemes and were not observed in Hannah’s babbling. I have no explanation for this. In addition, /ddj/ was included in the inventories of both the American-English and the Japanese children but was not found in Hannah’s inventory throughout the observation period. Lastly, the fricatives /b/, /f/, and /dj/ were never observed in Hannah’s babbling. Again, I can offer no explanation for this difference.

With regards to vowels, the only real difference between Hannah and the combined inventories of the reference groups is with the mid-front-rounded vowel /ø/. I consider this an anomaly because this phoneme was observed in the babbling of the American-English subject. Since this vowel is not found in English, it is possible that the referent was unique to have this vowel.

Throughout the entire observation period, Hannah showed an incredible diversity in the forms of consonant clusters that she produced. She uttered many examples of consonant clusters found in adult speech (/sk/, /bl/, /sn/, /br/, /st/, /pl/ and /kw/ to name a few.) I addition, she uttered many more examples of consonant clusters that are impossible in English (/tk/, /dlg/, /kz/, /pb/, /bv/, /tls/, /qz/, /vz/, /gx/ and /gd/ are but a few.) I can offer no explanation for this other than to say that babbling is very complicated and very individualistic.

CONCLUSION

After analysis of the data obtained during the research sessions with Hannah, several observations can be made that answer my original research questions. In response to my first research question, “What is the phonemic inventory of an American-English/ Japanese bilingual child during the babbling stage?”, a simple answer can be found in tables 5 and 6 on page 8 of this paper. I say simple because this answer falls short of providing and explaining the full range and complexity of a one-year-old child’s babbled speech. In this study I have not considered allophones, and I have probably either omitted or mistaken phonemes. However, I feel that the simplified version provided accurately depicts Hannah’s range of the most basic phonemes that she regularly produced during the research period.

To answer my second research question, I must turn again to tables 5 and 6: Is this child’s phonemic inventory comparable to both American-English and Japanese normally developing children of the same age? I would say that Hannah’s phonemic inventory, with the exception of a few phonemes, seems to closely match a combination of the American-English and Japanese samples used for comparison. However, they are not an exact match as I had originally predicted.

This leads to the next part of my second question: If not, are there phonemes lacking or extra? A comparison of the number of phonemes in Hannah’s inventory to a combination of the two reference groups shows some interesting figures. The Japanese child used for comparison had a phonemic inventory of 23. The American-English child had a phonemic inventory of 33. Hannah’s inventory yielded 38 phonemes. A combination of the two reference groups gives a total of 41 phonemes. Five phonemes found in Hannah’s inventory were not found in the combined inventory, and eight phonemes found in the combined inventory were not found in Hannah’s inventory. Among all three children, 13 phonemes were found in every child’s inventory, and 11 phonemes were found in only one of the three inventories. Therefore, this question cannot be answered as simply as the first two. Hannah has phonemes that the combined reference groups do not and lacks a number of phonemes that the reference groups have.

In light of this information, it should be reiterated that phonemic variation is a major theme in child language development. Even so, researchers in this field have sought ways to minimize variation in order to equally assess children with very different phonemic inventories. Dinnsen (1992) has developed a system for ranking developing children based on the complexity of specific phonetic features found in their inventories. According to this ranking system, Hannah could be placed at Level E, characterized by an inclusion of both [l] and [®], and [s] and [q]. This placement is somewhat odd because Level E children in Dinnsen’s research average two years old (1992). This is something that I would like to study in greater detail given the time and the subjects.

I would like to conclude with an idea from Schnitzer and Krasinski (1994). Their research sought to find out if a simultaneous bilingual child develops one phonemic system to represent the two languages or two separate phonetic systems. Their study targeted a child aged 1; 1 to 3; 9, and they concluded that the child developed one large phonetic system before achieving adult-like speech. However, this idea is interesting to me when applied to Hannah’s case. Although I have no way to prove it at this point, it is my belief that Hannah is developing one system of phonemes that will later be applied to both languages appropriately. Perhaps this belief will lead to further study of my daughter’s speech for quite some time to come.