Introduction
The acquisition of L2 is a process that is complex as many individuals may not achieve proficiency as expected. An individuals ability to achieve proficiency in pronunciation of an L2 is influenced by a complexity of factors besides the age factor, such as; socioeconomic status, gender, amount of exposure to culture, and others. These factors affect an individuals ability to reach L2 proficiency (Ellis 478). A good number of these studies have concentrated on finding the ages of the critical period (Lenneberg 198). A period during which abilities to learn language peaks and thereafter levels off and achievement of proficiency in pronunciation become a more daunting task. The studies examined depict the age at which an individual begins acquiring a second language to affect proficiency in pronunciation of that language.
Ellis (2003) depicts that, despite the rationale that adults can reach the same levels of proficiency as children, they face challenges in attaining proficiency on pronunciation in L2 compared to children (p. 480). Ellis (2003) attributes the overall problem to be that age as a factor influencing attainment of proficiency in pronunciation is not fully conceptualized. This is because learning a second language is a complicated process that cannot be fully comprehended. L1 acquisition occurs naturally and individuals require minimal efforts to succeed. Acquisition of L2, however, is more difficult depending on the age aspects of individuals attempting to learn the new language (Ellis 482). The main objective of this study is to establish the characteristics that influence the attainment of proficiency in pronunciation. These characteristics play a great part in determining whether adult Iranians can reach the same level of proficiency as children.
In this paper, I will first review the literature related to age variables that influence the attainment of proficiency in pronunciation in L2. I will examine in detail studies on the critical period of achieving proficiency in pronunciation of L2 following Lennebergs 1967s critical period publication. Critical studies examined include studies by Collier (1988, p. 76). Secondly, I will examine studies that follow Piagets conception of egocentric and socialized speech in determining the influence of age on pronunciation; Thirdly, I will examine studies on different forms of processing new language to attain proficiency in pronunciation; lastly, in this section, I will examine studies on the effects of the first language on L2 proficiency. The second section of the literature review will look at: the criticisms of age factor as a limitation to the realization of proficiency in pronunciation of L2; studies on effects of biological factors on age in achieving proficiency in L2; and studies on the effects of the rate of exposure to L2 in attaining proficiency in L2. Finally, I will examine the literature on how Iranians learn SLA to determine whether Iranian adults can reach the same level of proficiency as children
A Review of Related Literature
Can Adults Reach Same Level of Proficiency in Pronunciation as Children
As children, L2 is similar to L1 acquisition in that learners do not need to think about it (DeHouwer 167). The majority of children all over the world learn to speak at least two languages. Bilingualism is inevitable in every nation around the globe, in different classes of society and all age groups. The acquisition of a second language in children follows a similar process as they learn the first language (Perez 94). Children who develop proficiency in pronouncing L1 to communicate, think and solve issues easily acquire a second language in a similar way (Perez 96). Children who learn SLA learn it to carry all the knowledge about language acquisition they had received through their L1 acquisition. Tabors (1997, p. 12) posits that SLA for these children is not the process of discovering about language, rather finding out what language is.
there is variation, however, is how fast individuals learn the second language. Tangible evidence is not available of biological constraints to the acquisition of L2. No evidence depicts children as more advantaged in SLA compared to adults. The critical period of language acquisition ends by the time children reach adulthood. Adults face challenges in achieving proficiency on proficiency in L2 compared to children (Bley-Vroman 201). Adults find pronunciation as the main limitation in their second language acquisition. The ability to process speech in adults is altered through their experience of the first language. This incapacitates them in terms of achieving high levels of L2 proficiency. This topic requires further comprehensive research that focuses more on the levels that determine proficiency in pronunciation. However, this does not mean that adults cannot achieve fluency in pronunciation. Research has indicated that young adults and adolescents are better at learning second language (Coa later 24). Collier postulates that children tend to forget language fast compared to adults. This can lead to negative cognitive effects (DeKeyser 378). For instance, children before the age of five tend to learn a second language quickly followed by the loss of their first language. This impedes their ability to communicate to speak proficiently with their family members. (Hakuta 24). A number of studies try to explain the effects of age on the attainment of proficiency in pronunciation. Studies examined in this paper are examined as follows;
Studies on the Critical Period of Attainment of Proficiency in Pronunciation
Several studies on the influence of age on L2 attainment have followed Lennebergs 1967 publication on the critical period of acquiring a second language. The studies concentrate on trying to prove or dismiss the critical period hypothesis by comparing observations in the area of proficiency in pronunciation between children and adults. DeHouwer (2006 p. 297) dismiss studies that focus on pronunciation proficiency. These studies on pronunciation fluency discovered that after reviewing learners attainment of pronunciation in L2 after being exposed for three years, young learners achieved more fluency in pronunciation compared to adult learners (Lenneberg 480). Collier dismisses this research noting that the intention to test the critical period hypothesis concentrates more on the pronunciation aspect of language fluency, and the dichotomy of adult and child. Collier preferred researchers and educators to concentrate more not just on pronunciation by analyzing the period needed to attain proficiency in multiple content areas. In her analyses, she discovered that within 4-5 years, children of ages 8-12 attained set norms of proficiency. A group of children between ages 5-7 attained the set norms in about 8 years (Collier 43). The age group of 12-15 years had the hardest problem attaining the set grade norms. Most importantly, she also deduced that the influence of age recedes over time as L2 learner achieves more proficiency (DeHouwer 231).
According to Loup (1990, p. 266), it is not possible to attain proficiency in pronunciation unless first exposure occurs early, possibly before age of 6 in many people and by about age 12 in the remainder. Long avers that both proficiency in pronunciation is unattainable beyond the critical period. If the Critical Period Hypothesis affects SLA in the same manner as First Language Acquisition, adult L2 proficiencies would be lower compared to that of a native speaker (Birdsong 18).
Studies following Piagets Conception of Egocentric and Socialized Speech
A significant number of studies also followed Jean Piagets conception of egocentric and socialized speech. Studies on these aspects have led to the discovery of many other interesting aspects of speech in children during his investigations. As a result, Piaget triggered a lot of research about the most important area of language development during childhood (Cutler 70). The hypothesis advocated by Lenneberg and observations by Piagets observations contents a childs brain to undergo critical development between ages 2-12 years (Cutler 71). During this period, children have an innate ability to peak up on things rather faster, particularly language. DeKeyser (1995, p. 279) notes a study in this interest conducted to determine lexical comprehension in bilingual children. The yielded results indicated that children as young as 13 months were considered to be bilingual. At that age, these children were able to understand translation equivalents (DeKeyser 280). In addition, the research proves that comprehension is critical to the L2 attainment process and that it is noticeable as early as infancy (Cutler 72).
Studies on Different Forms of Processing New Language
Further, other studies point acquisition of language by children and adults to involve different forms of processing for language acquisition. In the Fundamental Difference Hypothesis, Bley-Vroman (1990, p. 201) states that L2 in adults needs mechanisms of solving problems that are explicit and general compared to children.. This bodes well ineffective grammar acquisition and less in attaining proficiency in pronunciation by adults. Apparently, DeKeyser (1995, p. 379) agrees with this thinking and contends that for adults to acquire a second language (L2), they need analytical thinking. According to Zobl (1989, p. 50), children achieve higher proficiency levels as compared to adults. This is occasioned by a change in the adult language faculty. In adulthood, there is a slight decline of the computational module hence the difference. Clearly, this may explain why adults cannot reach the same level of proficiency in L2 as children. Typically, there are different views concerning the relationship of age of L2 learning and the level of proficiency in pronunciation.
Studies on the Influence of the First Language on L2 Proficiency
There exist age limitations that prove the differences in language acquisition among children and adults (Hakuta 8). Adults find pronunciation as the main limitation in their second language acquisition. The ability to process speech in adults is altered through their experience of the first language. This incapacitates them in terms of achieving high levels of L2 proficiency. Thus, second language adults normally process input with mechanisms already attuned to their first language. Further investigations by Cutler (2002, p. 27) on adult speech segmentation discovered that adults do not utilize syllabification mechanisms when listening to their first language. This testifies how difficult it is for adults to reach proficiency levels as children. When listening, children engage in syllabification structures in the L2, unlike adults, thus, attaining proficiency in accent naturally. In this study, adult native English speakers engage a segmentation mechanism that is not stressful when listening to English (Cutler 47). They also followed the same strategy when listening to Japanese. Accordingly, Iranian adults cannot reach the same proficiency levels as children following the overview of these studies. Iranian adults just like Japanese speakers use moral related mechanisms in L2.
There are different perceptions about the relationship between the age of second language learning and the level of foreign accent/pronunciation. According to Long (1990, p. 251), a second language is spoken fluently before children attain the age of six. Those who learn L2 after age six will learn with a foreign accent. Similarly, Patkowski (1990) justified the critical period to explain why many adults speak their second language with a foreign accent (p. 254). However, this view was contested by Bongaerts (1999, p. 133) who discovered some motivated adults who began acquiring L2 after the critical period and spoke fluently. Moreover, Flege (1999,) also contested this view arguing Patkowskis suggestions were influenced by other circumstances other than pronunciation, such as speakers selection of words (p.239). He suggested 3 hypotheses that were concerned with proficiency in SLA (Flege 240). Exercise hypothesis was named as the first hypothesis as it explained ones ability to learn to produce and perceive speech which remains intact across the life span only if one continues to learn speech uninterruptedly (Flege 240). The unfolding hypothesis was named second as it explained the developed L1 phonetic mechanism at the time the second language begins (Flege 245). The third and last hypothesis was the interaction hypothesis. On testing it, Flege ascertained that the L1 and L2 phonetic systems in bilinguals could not be separated since there was a close interaction between them (Flege 246).
Studies on Effects of Biological Factors on Age in Achieving Proficiency in L2
Some biological factors explain why the achievement of pronunciation fluency is advanced in children compared to adults. According to Penfield (1959, p. 75), the flexibility or plasticity of a human brain recedes with age. As Hyltenstam (2003, p. 541) stated, acquisition of L2 proficiency was included. Hyltenstam (2003) concludes the process as one that plays a significant part in enabling neurons to make connections early in life. They explain that attainment of fluency in a second language is: a physical-chemical process in the brain necessary for providing neurons with nutrition so that they can extend the information transfer to larger distances in the brain (p. 540). Further, brain maturation is considered to take place when most of the cortical areas have completed the process of myelination (Hyltenstam 543). These biological processes are more active in children compared to adults. Therefore, these studies by and large explain why adults cannot reach the same level of proficiency as children.
According to Hakuta (2003, p. 31), there is a reduction in reduction in L2 fluency with age. This plays contrary to what the critical period hypothesis advocates. The critical period does not lead to the achievement of fluency in pronunciation of L2 among learners. However, it relates to specific cognitive mechanisms such as working memory capacity, speed cognitive processing and attention among learners (Hakuta, 41). Accordingly, Hyltenstan denies any:
co-variation between problem-solving, meta-linguistic abilities and language proficiency. If these cognitive explanations accounted for age-related differences, there would be different learning processes for children and adults, but research has shown otherwise (Hyltenstan 571).
An accurate interpretation of these studies indicates that late learners are hardly fluent in a second language. Children, on the other hand, acquire fluency in pronunciation. Additionally, fluency in pronunciation cannot be fully achieved by both children and adults. They contest that data deduced from studies on children and adult attainment of proficiency levels in L2 is under utilized. These types of learners are exceptional and cannot be easily differentiated from native speakers. In their perception, learning strategy has to be triggered from birth in order to avoid its decline. They attributed aging as the cause for decline in learning of people with increasing age onsets (Ellis 34)). However, maturation does not cause difference between exceptional and non- exceptional late SLA learners within the same Acquisition Onsets 3. They attribute social/psychological issues to what accounts to all these cases. In this way, they agree to existence of difficulty in attainment of proficiency in pronunciation levels among adults.
There is similarity in achievement rate of proficiency in pronunciation among normal developing children. This occurs irrespective of differences in patterns of interaction between parents and children. Inherently, learning in children occurs in a systematic pattern. The age factor is necessary in enhancing proficiency in pronunciation/accent of second language acquisition. According to Ellis (2009) children are more successful in being proficient in pronunciation of second language compared to adult (p. 329). Age The relationship between age of learning and achieving proficiency in L2 is backed by Critical Path Hypothesis approach. In this hypothesis, Lenneberg (1967) posits that proficiency in language must occur before puberty for the learner to achieve native like proficiency (p. 330).
Studies on the Effects of the Rate of Exposure to L2 in attaining proficiency in L2
Substantial variability in achievement of proficiency in pronunciation among learners exists. A number of factors underlie this variability in proficiency in accent among learners of which age difference being one of the factors. In order for an individual to achieve high proficiency in pronunciation, one has to begin being exposed to new language at an early age. The effects of age on fluency in pronunciation are a factor used in determining individual differences in language acquisition (Krashen 222). There are substantial studies that support the assumption that children become more proficient in pronunciation compared to adults. We may wonder whether one needs to begin new language before attaining a certain age in order to achieve proficiency in pronunciation (Loup 73).
In studying the influence of age on proficiency in pronunciation, one needs to separately consider its impact on the route of acquisition, rate of acquisition, and achievement of proficiency or fluency in pronunciation. The age factor does not have much effect on proficiency in pronunciation as regards to the route of acquisition. Krashen (1979, p. 221) showed using bilingual syntax measure, that adults acquired grammatical morphemes in a manner similar to L2 learning children. However, age effect is essential in the case of pronunciation. In normal adaptive settings, children learners achieve more proficiency in pronunciation than teenagers or adult.
A number of perspectives explain the success of proficiency in pronunciation in Second language attainment (Ellis 3). Learners need to understand what is to be learnt, how to learn it, and why it should be learnt. However, the process of attaining proficient accent in second language is complex and involves a number of interrelated factors (Ellis 4). These perspectives discuss how attainment of proficiency in SLA is clearly influenced by age differences (Brown 329). Although these approaches have resulted to success in learning second language and achieving proficiency, it remains that children attain proficiency in pronunciation faster than others. Studies in this area have looked at children and adult variables and their capacities to attain proficiency in second language.
Age as a factor of individual differences affects achievement of proficiency in pronunciation of second language especially among adults. According to Ellis (2000, p. 32), it is not easy to arrive at a coherent picture of individual differences. He categorizes the variables involved in individual differences into three main classes: learners belief about language learning was classified as the main type. Learners under this category have pre-conceived ideas about matters such as significance of language aptitude, nature of learning new language, and strategies that work well; secondly, Ellis (2000, p. 5) recognizes affective states as the second main type of variable that affects proficiency in pronunciation of second language. He cites fear of beginning to learn the second language by some learners, and over confidences by others as reason. For Iranians fear of embracing Western values compounds this fear. Other learners develop anxiety due to competitive natures and how they perceive whether or not they are progressing (Coppieters.545).
Szuber (2006, p. 125) posits that most studies on language tend to concentrate on early childhood compared to adulthood. In this regard, adolescence as an interesting period is commonly ignored. World over, majority of adolescents are either born in a foreign country or speak a language other than their native languages (Szuber 121). Acquisition of second language in this group is first rising and more attention must be accorded by researchers and educators alike (Szuber.126). It is common knowledge that children achieve high proficiency levels in normal settings. Adults on the other hand, may attain their proficiency in pronunciation in a structured setting such as classroom. This attests that adults cannot achieve same level of proficiency in pronunciation in L2 compared to children.
What are the Criticisms of Age Factor as Limitation to Achieving Proficiency in L2
There have been numerous attempts to criticize the existence of age limitations as shown by L2 learners who acquired fluent accent. The prominent and critical feature is lack of foreign accent when adults speak second language. Let us have a look at these studies. According to Coppieters (1987, p. 544), the first study conducted to ascertain the effects of age on fluency on second language pronunciation was carried out by Coppieters. Twenty one foreign learners were identified as the sample population for the investigation. Semantic judgment task and follow up interviews were the main involvement of this sample group made up of French learners (Coppieters 545). These learners were selected as they had no fluent foreign accent. The overall performance of these learners was discovered to be under that of native accent controls despite the fact that they had no fluency in accent. Some of these experimental investigations have shown that achievement of pronunciation proficiency is not impossibility for adult learners of L2. An investigative study sample in which proficiency in pronunciation was noticed includes the research work of Birdsong (1992, 700) and Bongaerts (1992, p. 699). These researches dealt with a variety of grammatical features which included proficiency in pronunciation. In these researches, the incidence of fluency in pronunciation achievement ranged from 5% of the sample to 15% or above (Birdsong 701). Nevertheless, evidence relating to proficiency in pronunciation in adult SLA is ambiguous. For instance, 6% of the adult participants in the research of Flege et al. (1999, p. 85) performed with proficiency in pronunciation, but all had ages of arrival younger than 16 years.
Birdsong (1992, p. 706) discovered majority of French adult learners performed well just as native speakers. This is supported by the fact that out of twenty one French learners, fifteen were able to achieve the same level of hard grammar task as the native speakers. Bongaerts (1992, p. 707) concentrated his studies on phonology. He studied L2 learners of English and French among fluent Dutch students (Bongaerts 708). These learners were selected because of their fluency in pronunciation in English and French. They were requested to pronounce a series of sentences aloud. Words that Dutch speakers found challenges in pronouncing were included in sentences. Interestingly, a good number of these learners performed well as native speakers at all levels. Bongaerts (1992, p. 712) on their part studied pronunciation of advanced and naturalistic learners of Dutch as a second language. Bongaerts selected 30 educated learners with different first languages and different age onsets. The selected ages ranged within 11 and 34. Observations indicated that two participants (age 21 and 14) excelled as native speakers. Moyer (1999, p. 82) researched fluency in pronunciation/accent among 24 year olds American adults and were discovered to very fluent of German. These American adults were taken to German to learn German language to determine their fluency. They were offered work to read aloud. This work had a word list, paragraph and full sentences. Apart from this, each Germany judge singly evaluated and awarded marks on the American adults speech samples. The outcome indicated that the judges were able to differentiate between the native speakers and non-native speakers. Curiously, only one speaker was judged to have spoken like natives cross all pronunciation work provided. This was an exceptional adult learner who had high motivation for German language fluency (Moyer 87).
When these learners were exposed to shorter tasks which included word list reading, researchers found movement towards more achievement of fluency in ratings. Foreign accent emerges once the task is extended to include full sentences and paragraphs. Hyltenstam interprets this as a risk as the studies seemed to concentrate on skills rather than concentrate specifically on pronunciation proficiency (Hyltenstam 539). They were concerned whether these adult second language learners who excelled as fluent speakers would have done so if they had been given longer tasks that required spontaneous speech (Hyltenstam 540). However, Moyer (1999, 87) notes that challenges involved in engaging long naturalistic speech to evaluate pronunciation fluency. This is because there are other linguistic features which could influence second language learners performance. These linguistic features include lexical and syntactic features.
According to White (1996, p. 234), L2 learners who seem to attain proficiency in pronunciation differed from native speakers in subtle ways. Their investigations they considered the control group in a strict sense for the purpose of separating native speakers from non-native speakers. It was observed that majority of subjects deemed to be close native began learning English as L2 before age 12. However, non-native speakers were observed to begin learning English after attaining age 12. Significant contrasts were realized between native and non-native control groups on the parameters that were assessed. Universal grammar was found to be unaffected by age as late second language learners were also able to attain native-like fluency (White, 234). Hyltenstam (2003, p. 353) dismisses Whites investigations strongly for considering individuals who spoke French as their first language arguing that, in spite of having been very rigorous in their selection criterion. Therefore, it is natural that the speakers did not encounter any challenges regarding these aspects.
In other studies, investigators were concerned with young learners finding out whether it was possible to find SLA learners who attained high levels of accent at earlier ages. Hyltenstam (2003) tested:
grammatical and lexical performance of 24 highly proficient Spanish and Finnish L2 learners of Swedish with Age Onset of six years or earlier (16 subjects) and seven years or later (eight subjects) (p. 356). The age of 6 was discovered to be a critical period that differentiated between near-native and native-like ultimate achievement of proficiency (p. 364).
However, he observed that, not all early learners reached native-like proficiency hence his conclusion that early age onset is not the only requirement for sufficient acquisition of native-like proficiency.
Finally, Hyltenstam (2003) concluded that, there were significant differences between first language speakers and second language speakers regardless of their age onsets (p.234). The studies indicate that delay in age onset has an impact on the level of language proficiency (Hyltemstam 241). It is apparent that, when studies conducted on adult L2 learners and those conducted on childrens SLA learners are compared, both did not find learners who attained overall native like proficiency. When studying late and advanced L2 learners, Hyltemstam observed some limitations (Hyltemstam 160). Other studies also observed that advanced SLA learners could not achieve full proficiency (Coppieters, 1987, p. 544).
In relation to mistakes typical of the fossilization processes, a learner has to understand his own learning strategies for the purpose of monitoring his fluency in L2 pronunciation. Critics however pointed out those subjects performed fluently as other speakers in other areas that were not specifically investigated (Birdsong 9). The investigator found that those speakers who were as good as native speakers conformed to native norms. Non-native features as explained by Bongaerts (1999, p. 544) contend that non-native characteristics go a step further than determining proficiency in pronunciation in his advanced control group when making free oral speech. Considering this evidence, Hyltestam (2003, p. 564) states exceptional learners with ability to acquire native-like proficiency in some areas of second language, although not at all levels. This can happen to adult learners who are highly motivated to achieve high proficiency levels in L2 (DeKeyser 201).
Common evidence exists on the effects of age on pronunciation proficiency. Syntactic complexity among learners starts forming at the age two according to (Lenneberg 330). Singleton on his part proposed six months as an early age since during this period, phonetic sensitivity is already present for different categories. Alternatively, he proposes an early age to be at birth because at birth children are sensitive to segmental and prosodic differences (Singleton 89). In addition, he point out that the first language has different domains and therefore there are different age onset for the different domains (Singleton 54). Criticisms allude that low age onset (children) does not guarantee high level proficiencies in pronunciation as this process is directly influenced by other factors.
Can Iranian Adults Reach Same Level of Proficiency as Children
In Iran, proficiency in pronunciation in foreign languages is taught through a context-restricted environment. In this environment proficiency in pronunciation is learnt by classroom practices that use specific textbooks and teachers classroom work management for children and adult learners. Learners in Iran do not experience support from social contexts outside the classroom. According to Sadighi (2000), fluency in foreign languages such as English was formally taught from the second grade of junior high school after Iranian Revolution (p. 14). Presently, proficiency in English fluency is taught from the first grade of junior high schools (at the age of 10-11) (Hussein 13). The Iranian Ministry of Education is taxed with res0ponsibility of compiling, developing and publishing textbooks for foreign languages. The Ministry of Education also publishes teaching materials for public and private high schools nationwide (Hosseini 11).
The rate of proficiency in pronunciation is favorable to adult learners than children learners when the amount of exposure to the language is controlled. However, the amount of exposure of foreign languages to Iranian adult learners is restricted, thus cannot reach high levels of proficiency on graduation. Most emphasis of proficiency in pronunciation learning in 1990s concentrated on reading skills to allow learners read and translate English texts more easily. Iranian general curriculum placed emphasis on developing learners grammatical knowledge in reading and translation. It placed less focus on proficiency in pronunciation. Therefore, most techniques used by high school teachers involve grammar translation to prepare learners for expectations of Iranian national curriculum. The curriculum puts more emphasis on grammar and less concern on enhancing proficiency in pronunciation. For this reason, therefore, it is not easy for adult Iranian learners to reach high proficiency levels in pronunciation as children.
Proficiency in pronunciation of second language demands contact with native speakers. Tourism and travel is another factor to be taken into consideration to Iranian learners mastery of English as a second language. Few tourists visit Iran, and only visit historical cities like Isfahan and Shiraz, and only a few make visits to Tehran where majority of Iranian students are learning English (Menashri 11). Tourists make it possible to individuals to communicate in English even if the state restricts media for learners on religious grounds. Travelling also assist greatly in terms of practicing the language. Due to prohibitive bureaucracy, Iranians find it extremely difficult to travel abroad. It i