RP SBE vowel formants
This page introduces a spectrographic study of the monophthong vowels of five speakers of RP (the same five speakers who were introduced in Part 1). Together, they cover 100 years (birth years from 1874 to 1961), offering a snapshot of some of the changes reported in RP during that period. In Part 1 I suggested that the MOUTH and GOAT diphthongs would discriminate between RP and other varieties of Southern British English ([aʊ] and [əʊ] respectively for these five RP speakers, [æɔ] and [aʊ] respectively for the five home counties and London speakers illustrated there. Now there’s an opportunity to check for differences in the monophthong vowels.
Expressions like MOUTH, GOAT are keywords used by John Wells (1982, Accents of English, C.U.P.) to denote lexical sets that participated in various dialect developments or sound changes (merging, splitting, shifting etc), and are useful for comparing accents.
RP speakers are not easy to come by. Estimates suggest they amount to about 3-5% of the UK national population (summarised in Part 1), and their social status means they are not all that accessible. Most of us would hardly ever hear RP spoken if it weren’t for the theatre, cinema, radio or television. The five RP speakers presented here were chosen because public recordings are readily available. But it turns out that two of them have adopted RP, which need not matter provided acquisition was successful. William Somerset Maugham’s first language was French, according to his Wikipedia biographer, although his parents were English and his father was legal adviser to the British Embassy in Paris; orphaned at 10 (1884), he stayed with his uncle in Whitstable (Kent), in Estuary English country; he boarded at King’s School in Canterbury, leaving around 1890 at 16 to continue his education at Heidelberg and then at St Thomas’s Hospital (London); getting teased for his English at school was an assumed cause for his stammer, and a measure of his progress towards RP. The other speaker with adopted RP is William Hague (politician), who grew up in Yorkshire; journalists have frequently teased him for his Yorkshire accent, but there’s scarcely any trace in the recordings I’ve heard; John Wells (1997, Our changing pronunciation, Transactions of the Yorkshire Dialect Society xix, 42-48) remarks on Hague’s STRUT vowel, so that will be checked; there was just one slip in the public address analysed here, when he missed the TRAP-BATH split, saying [vast] rather than [vɑːst] for vast.
Listen to these five RP speakers again, ordered by birth year (William Somerset Maugham 1874, Harold MacMillan 1894, Ian Fleming 1908, Kingsley Amis 1922, William Hague 1961).
Listen to the five home counties SBE speakers from part 1. The first two are actors and comedians (popular home counties SBE sociolects), then a professor, a photographer, and a professor (standard home counties SBE sociolects).
Figure 1: Example of a narrow band spectral slice, showing the partial structure of a vowel to help determine which partials are included in a formant.
Figure 2: F1/F2 vowel diagram for RP speaker William Somerset Maugham.
The recordings were all continuous speech, interviews or public speeches, 3-5 minutes
for each speaker. The recordings had unfortunately been compressed by MP3 to low quality to facilitate handling on the web. Consequently broadband spectrograms and LPC formant tracking were not always distinct. Narrowband spectrograms turned out to be easier to work with, by identifying which harmonics were included in a formant, and which were not. Formants were sampled at moments where vowels were least affected by neighbouring consonants, as indicated by formant transition movements. The formants were then measured on the computer screen from spectral slices taken at the selected moments (Fig. 1). Stressed vowels in focally accented words were chosen, 3 to 5 instances of each phoneme depending on availability. There were few examples of the FOOT vowel, some speakers not providing any in their speech samples.
Figure 3: F1/F2 diagram for RP speaker Harold MacMillan
Figure 4: F1/F2 diagram for RP speaker Ian Fleming
Figure 5: F1/F2 diagram for RP speaker Kingsley Amis
Figure 6: F1/F2 diagram for RP speaker William Hague
The F1/F2 diagrams for each RP speaker are shown at Figures 2-6. Since the 1950s, it’s been customary to interpret F1 frequency as degree of tongue lowering, and F2 as degree of tongue fronting, with reference to the Bell vowel model (Sidney Wood, 2012, The Bell vowel model, this website). A harder interpretation (Martin Joos, 1948, Acoustic Phonetics, Language Monograph 23, supplement to Language 24) claimed that phonetic judgments of tongue height and tongue position were exclusively mental analyses of formant patterns, mistakenly expressed as articulation. In either case, recall that the Bell vowel model was already flawed before it was launched in 1867 (Sidney Wood, The acoustic weaknesses of Bell’s vowel model, this website).
The frequency scales of the vowel diagrams are compressed to the Mel scale, so that equal linear intervals are perceptually equal in Mels (Stevens, Stanley, Volkman J, & Newman E. B., 1937, A scale for the measurement of the psychological magnitude pitch, Journal of the Acoustical Society of America 8, 185–190; Fant, Gunnar, 1968, Analysis and synthesis of speech processes, in B. Malmberg (Ed.), Manual of Phonetics, Amsterdam, 173-177). Other psychophysical scales are also found in the literature, a straight logarithmic transformation (yielding linear octaves and semitones), and Bark transformations (based on auditory critical bands).
Figure 7: The effect of degree of constriction (Amin), and degree of mouth opening (A/l) at the four constriction locations for vowels. Superimposed for comparison is an F1/F2 diagram for a home counties SBE speaker (recorded from the radio in the 1970s). (From Wood, Journal of Phonetics 7, 25-43.)
The true relationship of vowel formant frequencies to articulation is more complex than Bell proposed. For example, the FLEECE, KIT and DRESS zones in Figures 2-6 require the vocal tract to be narrowed along the hard palate; the GOOSE and FOOT zones require a narrowing along the soft palate; the THOUGHT zone requires a narrowing in the upper pharynx; the TRAP, STRUT, BATH and LOT zones require a narrowing in the lower pharynx (Sidney Wood, 1979, A radiographic analysis of constriction locations for vowels, Journal of Phonetics 7, 25-43). Figure 7 demonstrates how F1 and F2 are varied at each of the four locations by adjusting the degree of constriction (tongue body activity) and degree of mouth opening (lip and jaw activity). Additionally (not shown on Fig. 7), elevating or depressing the tongue blade, larynx, or velum will also modify formant frequencies. Although only F1 and F2 are shown, all these articulations affect all the formants.
Figure 8: F1/F2 diagram for a speaker of home counties SBE, partially modified to RP. From Wood, Working Papers 23, Lund
Figure 9: F1/F2 diagram for a speaker of home counties SBE. From Wood, Working Papers 23, Lund
The speech samples from the five speakers of home counties SBE, from Part 1, have not yet been analysed. In the meantime, Figs. 8 and 9 show F1/F2 vowel diagrams for two other speakers of home counties SBE (born in the 1910s and 1930s), for comparison with the RP examples. Figure 7 also includes a diagram for a third speaker of home counties SBE. All three are adult male.
Potential differences between RP SBE and Home Counties SBE
A quick comparison of Figs. 2-6 with Figs. 7-9 shows that any accent differences between RP and home counties SBE are fairly discrete among the monophthong vowels. Why should any differences matter? For the linguist, they provide criteria for discriminating between accents or dialects, and establishing directions of sound change in different speech communities. For the language teacher, SLP therapist, or dialect coach, they offer criteria for assessing progress. For a speech community, they signal group identity and membership.
The potential differences, as recorded by Daniel Jones (1918 and later, Outline of English Phonetics, Teubner, later Heffer) and A. C. Gimson (1962, An Introduction to the Pronunciation of English, Arnold), concern the THOUGHT (together with NORTH and FORCE), LOT, and STRUT vowels. More recent observations concern the GOOSE vowel.
- THOUGHT. Jones and Gimson describe the RP THOUGHT vowel as [ɔː], while the home counties SBE examples (Figs. 7-9) show [oː]. Wells (1982, vol. 2, p. 310) reports [oː] in popular London speech. On the formant diagrams, [o] is closer to [u] (towards F1 around 400Hz), while [ɔ] is further away from [u] (towards F1 around 500Hz). Jones gave Northern English as an example of regional [oː]. Gimson had no regional example for [oː], but found it increasingly common in Advanced RP (Wells’ U-RP), Wells (1982, vol 2, p. 293) dating this change to the past half-century without reference to any particular variety of RP. Any timbre shift to [oː] for RP THOUGHT would mean that this difference between RP and home counties SBE is gradually disappearing.
Listen to examples of the [ɔː]-like THOUGHT vowel by the five RP speakers:
Three examples from each: often, forties, course; short, course, more; straightforward, war, taught; endorse, importance, more; lord, forebears, your.
Listen to examples of the [oː]-like THOUGHT vowel by the five home counties SBE speakers from Part 1:
Three examples from each: performance, glory, warzone; absorbing, exhausted, dawn; thoughts, talk, endorsed; sports, important, forties; withdrawing, proportions, forces
- LOT. Jones always transcribed the RP LOT vowel as /ɔ/, but it’s clear from his descriptions that the actual pronunciation was a rounded [ɑ], i.e. [ɒ]. Gimson adjusted the phonemic notation to /ɒ/. This timbre contains a hint of [ɑ] and Figs. 2-6 show the LOT zone very near the BATH zone, with F1 around or above 600Hz. Neither Jones nor Gimson mentioned any regional [ɔ]-like variants, while these five home counties SBE examples tended to say [ɔ]. This timbre does not contain any hint of [ɑ], and Figs. 7-9 show the LOT zone nearer the THOUGHT zone, with F1 around or below 600Hz.
Listen to examples of the [ɒ]-like LOT vowel by the five RP speakers:
Three examples from each, some repeated: honest, honest, competent; office, historic, economy; watch, foreign, job; neurotic, moral, stocks; honouring, colleage, policies
Listen to examples of the [ɔ]-like LOT vowel by the five home counties SBE speakers:
Three examples from each: dots, wants, Hollywood; from, Johnson, comedy; not, gods, teleology; modern, lots, spin off; authority, strongest, crossing.
- STRUT. Daniel Jones (followed by Gimson) always described an unrounded [ɔ], i.e. [ʌ]. Jones, and Gimson, recommended [a] as a best subsitute if foreign learners fail to obtain the precise sound. Jones also observed that [a] “is actually used as a substitute for it in some English dialects (including London)”. Figures 7-9 confirm an [a]-like STRUT vowel for those three home counties SBE speakers shown there. Strangely, Figures 2-6 show that the five RP speakers also pronounced STRUT as [a], Harold MacMillan and Ian Fleming slightly darker coinciding with the [ɑ] of BATH (differentiating STRUT from BATH by quantity). What appears to be an expected theoretical difference ([ʌ]/[a]) between RP and home counties SBE just didn’t occur in any these samples.
Listen to examples of the [a]-like STRUT vowel by the five RP speakers:
One example from each, repeated three times: sometimes; country; publisher; eachother; hundred.
Listen to examples of the [a]-like STRUT vowel by the five home counties SBE speakers:
One example from each, repeated three times: lucky; company; punishing; summer; structured
- GOOSE. Jones always described the RP GOOSE vowel as having a more advanced tongue position than cardinal [u], even more advanced after /j/. This means that this [u]-like vowel is not so dark as cardinal [u] (i.e. F2 would not be as low as 700 or 800Hz), and even brighter after /j/ (F2 perhaps around 1200Hz or more). Gimson followed Jones, adding a reminder that English does not have to respect an /u/-/y/ contrast, allowing more variability for /u/. Jones didn’t mention any regional variants, but Gimson reported that centralization is a characteristic of the regional dialect of London, adding that “considerable centralization amongst RP speakers is, therefore, inhibited to a certain extent for social reasons”. Jonathan Harrington et al. (2011, The contributions of the lips and the tongue to the diachronic fronting of high back vowels in Standard Southern British English, Journal of the IPA 41, 137-156) cite a number of reports from Englishes around the world, confirming the widespread brightening of the GOOSE vowel, including [y]-like allophones. Figures 2-6 show that these five RP speakers follow this same progression, darkest around 1900 and steadily brighter through the 20th century (bearing in mind that these F2 ranges might also reflect the small sample sizes). WSM had the darkest F2 range, 800 -1300Hz, then HM 900-1400Hz, then IF and KA 1100-1500Hz, and WH 1000-1700Hz. There is similar variation in the three home counties SBE speakers (Figs. 7-9): 1100-1400Hz, 800-1200Hz, 1300-1600Hz. This small set of speakers suggests no real difference over time between RP and home counties SBE accents during the 20th century, both accents tolerating ever brighter renderings as the years passed. Although a closer look at more RP speakers might show RP lagging behind.
The vowels of the five home counties SBE speakers, heard in the recordings above, will be reported later once they’ve been analysed. The topic of GOOSE fronting will also be looked at more closely in a future article.
©Sidney Wood and SWPhonetics, 1994-2014