3.2 Formant Spaces Comparison across Accents                                  

Figure 9 shows the average of the first, second, third and fourth formant frequencies of British, Australian and American accents. Except for the vowels /aa/ /ah/ /oh/, other Australian vowels have lower F1 than the British. American vowels display higher F2 than Australian except for /er/. On average, 2nd formants of vowels in Australian are 11% higher than those of British and 8% higher than those of American. In formants F3 and F4, Australians consistently displays higher formant frequencies than British. American speakers also have higher F3 and F4 than British speakers except for /er/.  An analysis of the formant values of table 1 shows that the 2nd formant is the most dynamic of the formants with a frequency variation across the phonemes of up to 2 kHz. From tab1e 1, for Australian the average vowel frequency of the 2nd formant varies from about 900 Hz for /ao/ to 2600 Hz /iy/. Male speakers from these accents illustrate a similar set of patterns to females. In phonetics, vowels front or back movements are regarded as correlated with F2 while high and low movements are associated with F1. 

In phonetics, vowels’ front or back movements are regarded as correlated with F2 while high and low movements are associated with F1. Front movement of a vowel means it has higher F2 while back movement corresponds to lower F2. Similarly high movement of a vowel means it has lower F1 and vowels move towards to close vowels while low movement corresponds to high F1 and vowels move towards to open vowels.  Figure 10 illustrate formant spaces of the three accents. It can be noticed that compared to British and American:

·        Rising of the lax vowels /ae/ and /eh/ in Australian

·        Fronting of the open vowel /aa/ and the high vowel /uw/ and /uh/ in Australian

·        Fronting and rising of the lax vowel /er/ in Australian

·        /iy/, /eh/ and /ae/ in Australian are closer

With the vowels /ae/ and /eh/ in Australian rising towards /iy/, the result is that /iy/, /eh/ and /ae/ are much closer in Australian formant space than in those of the other two accents. Wells suggests that in Australian /iy/, /eh/ are pharyngealized and /ae/ is nasalized. In addition, the vowel /er/ in Australian is more closed (has a lower F1) and more fronted (has a higher F2). The noticeable fronting of /aa/ in Australian makes /ao/ the only real back long vowel in Australian

The formant spaces of Figure 10 also show that American /aa/ is slightly opener (has higher F1) compared to the British /aa/ and American /ah/ is centralized compared to British and Australian accents.  The most strikingly different feature in the formant space of three accent is that of the American /ao/ which is a much lower vowel (i.e. has a higher F1) and more Fronted vowel (i.e. has a higher F2) compared to British and Australian perhaps due to tendency of /ao/ and /oh/ to merge in American English.

From the differences in the formant space, it can be seen that the formants play a central role in conveying different English accents. In particular, the second formant is considered to be most affected by accents.                                                                                                                                                                                

Figure 9: Comparison of Formants of Australian, British and American (female)

                    

  Figure 10:  Formant Space of Australian, British and American (female)

 

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