Suboptimist

I know you missed me.

December 13, 2007 – 4:33 pm

EDIT: Also, it seems the tables don’t show up. Check the PDF.

EDIT: Also, references.
Anyway, I had a few people request I post my phonetics paper here. The PDF version can be found here. If you want charts and pretty pictures, you need it. This is actually not the final copy. That is on my flash drive, and I am too lazy to go get it. Anyway, enjoy, if you’re really into it.

Abstract

Recent studies such as Zaba et al. (2007) reveal strong relationships between native English speakers’ knowledge of front and back vowel contrasts in their language and their detection of Arabic pharyngealization contrasts. Previous studies have focused primarily on pharyngealization contrasts on the right margin of monosyllabic words. The goal of the present paper is to understand whether a similar phenomenon is at play when the target contrast occurs at the right margin of monosyllabic words and to act as a pilot for future inquiry into non-native perception of pharyngealization contrasts. Discovered were an ability for L2 subjects to discriminate the contrast, without necessarily exploiting L1 phonology.

1. Introduction

Among the more difficult requirements placed upon a language learner is perception and mastery of contrasts foreign to his or her native language. While it’s understood that adults can discern minute acoustic differences in speech signals, most of adult life is spent ignoring phonological contrasts irrelevant to his or her language. A question does arise from this point – to what extent do the phonologies of speakers of two distant languages overlap to the end of discerning contrasts native to one language, but foreign to the other? One such case of foreign contrasts potentially able to shed light on this problem is that of Arabic pharyngealization contrasts. The present paper is an investigation of non-native perception of this contrast in right-margin environments relative to facts of L1 phonology. The remainder of this paper is divided into three main parts. The first is a discussion of the contrast being studies, background research into pharyngealization in Arabic, and research conducted into non-native perception of pharyngealization contrasts, Second, an explanation of the experimentation done in accordance with this study and its results. Third, an acoustic analysis of Arabic pharyngealization in attempt to shed light on explanations for the experimental results. I conclude with implications of this research and ideas of how to follow up on conclusions presented.

2 Previous research

2.1 Pharyngealization contrasts

A majority of Arabic dialects contrast pairs of plain and pharyngealized alveolar obstruents. Observe the following minimal pairs in table 1:

[Table 1]

To the English-speaker’s ear, these contrasts are each perceived as variations of their familiar alveolar obstruents in this manner: /dˁ/, /d/ ~ /d/.

Acoustically, pharyngealized obstruents correlate most closely with a lowered F2 value in vowels in its surrounding environment. Jongman & al-Masri (2004) and Jongman et al. (2007) found significant lowering of F2 values in vowels in the target consonants and syllables to the right or left of pharyngealized targets. Additionally, Jongman et al. found a pattern of progressive lowering of F2 values from the onset to the offset of the adjacent vowels in pharyngealized environments. This significant lowering effect is expected, according to Card (1983) as a correlate to the articulatory feature of [+RTR], retracted tongue root. The greatest effect of vowel lowering was found on the vowel /ӕ/, which varies allophonically as [a] ~ [ӕ] The acoustic portion of this paper will investigate this effect in greater detail.

2.2 Perception studies

Remarkably few studies have been conducted into non-native perception of pharyngealization contrasts. Zaba (2007) found that non-native listeners were capable of discriminating pharyngealization contrasts and that it corresponded with their knowledge of English front-back vowel contrasts. As a matter of fact, some beginning Arabic textbooks instruct learners to listen to the vowel in the environment of pharyngealized consonants to discern the difference (Batal et al., 1995). Perhaps unsurprisingly, she found the greatest effect with /ӕ/. In pharyngealized environments, listeners perceived this vowel as /a/, as in their native [cat] – an exploitation of their native phonology. Her study focused on pharyngealization contrasts in left-margin environments of monosyllabic words. In the experimental discussion here, I investigate if the same effect is present on the right margin of monosyllabic words.

3. Experiment

3.1 Methods

3.1.1 Talker

The speaker is a 20-year-old student at the University of Utah and a native speaker of the Jordanian Ammani dialect of Arabic. He has no documented speech or hearing disorders.

3.1.2 Listeners

Participants (n=9) were recruited from the University of Utah campus, the University of Utah Linguistics department, and friends of the author. All were age 18-31. All were native speakers of English with no reported Arabic fluency. No participants had any documented speech or hearing disorders.

3.1.3 Stimuli

The talker was recorded saying sentences printed in Arabic script on note cards in the form of [Ɂiħki ____ kəma:n mərah] ‘please say ____ again.’ The target words were monosyllabic non-words in the form CVC. The first consonant was [k] [b] [m] or [h]. The vowel was either [a] [i] or [u]. The final, target consonants were alternately a plain alveolar obstruent or a pharyngealized alveolar obstruent. Stimuli were recorded using an iPod(TM) video with a MicroMemo(R) attachment and a SkullCandy(TM) (model) microphone. Stimuli were recorded at 16 bits and a 44100 Hz sampling rate. Target words were excised from sentences using Praat (Boersma, 2007) and Audacity editing software with a Dell 1510 laptop computer. Stimuli were randomized and presented using Apple iTunes software with shuffle function enabled, and played through Logitech Digital Precision gaming headset.

3.1.4 Procedure

Subjects were presented with two tasks to complete. The first was a vowel identification task in which listeners were presented with randomly selected CaC/Cˁ CiC/Cˁ and CuC/Cˁ items presented in isolation and asked to match the vowel in the item to the vowel in an English word with {a, ӕ, e, i, ɪ, u, ʊ, ʌ} (adapted from Zaba, 2007). The second task was an AXB discrimination task in which listeners were played 56 randomized sound clips with 3 tokens each of [A X B] and instructed to indicate whether [X] was more like [A] or [B]. 0.5 seconds were placed between each token, with 2 seconds between each sound clip.

3.2 Results

3.2.1 Vowel identification

When presented with CaCˁ/C tokens, all participants identified the vowel as /ӕ/ in both pharyngealized and non-pharyngealized environments. For CiCˁ/C and CuCˁ/C tokens, participants responded in the following manner.

[Table 2]

Plain

Pharyngealized

[Table 3]

Plain

Pharyngealized

3.2.2 AXB task

All participants scored significantly above the chance threshold of 50-percent (t(8)=8.07 p < 0.0001). It was expected that participants would score higher on /a/-stimuli. However, this was not the case. Instead, participants performed best on /i/-stimuli. See figure 2.

This finding was unexpected considering the findings in Zaba (2007) where the greatest performance was found in /a/-stimuli. There is a possible phonetic explanation for this to be discussed in the following section.

The second step was to analyze the relationship between the vowel selected on the vowel identification task and the participants’ scores on the AXB discrimination task. An ANOVA revealed there was no significant effect (F[3,32]=1.56 p = 0.21). This is also in contrast to

findings in Zaba (2007) revealing a relationship between knowledge of front and back vowel contrasts of English speakers and performance on an AXB discrimination task with target obstruents on the left margin.

4. Acoustic analysis

F2 values were measured in Praat phonetics software (Boersma 2007) at the the initial vowel onset and the terminus of the vowel. Differences were measured for statistical testing. There was no significant lowering effect found for /a/-samples (p = 0.23). An insignificant lowering effect (p = 0.51) was found for /u/-samples, however there was also a raising effect before plain targets. This effect was attributed to stimulus design. There was a significant lowering effect for /i/-samples (p = 0.003). Additionally, there was a significant difference in F2-lowering in /i/-samples as compared to pooled /a/ and /u/-samples (p = 0.001). These statistical differences may also signify practical differences in terms of perceptible contrasts. See figures 3-9.

An additional interesting thing to note is the glide-like behavior if /i/-samples. The mean F2 change of these samples was approximately 1000 Hz, yielding a change from [i] in this vowel space to what would be expected as [ɰ] in the same space. These results stand as possible explanations of the discrepancies between this research and the work of Zaba (2007).

5. Conclusion

This paper attempted to explain non-native perception of L2 contrasts in light of exploitation of L1 phonological knowledge. However, the results showed that non-native speakers of Arabic can perceive a foreign contrast, but do not necessarily do so with any reliance on their native phonology. In fact, the significant perception scores in the AXB task may be the result of purely phonetic discrimination in light of the acoustic observations presented in the previous section. The implications of this are potentially far reaching – not all perception of foreign contrasts can be attributed to an overlap of L1 and L2 phonologies. I would, however, recommend that future research replicate this study with more robust methodology in a more controlled laboratory setting, which was untenable in this study. Additionally, a more detailed acoustic study comparing acoustic effects of differing pharyngealized environments – more specifically right versus left margins – should be conducted across various Arabic dialects.