Sound change in 19th century RP: Monophthongs

Seven examples of 19th century RP (the RP accent of people born in the 19th century) are examined for signs of some reported sound changes. This first post considers monophthongs.

The examples, ordered by birth year, are:

RP12: Robert Baden-Powel 1857-1941; Baron Baden-Powell; army general, scout movement; gramophone record 1937
RP06: Stanley Baldwin 1867-1947; Earl Baldwin of Bewdley; politician, industrialist; political broadcast
RP13: Neville Chamberlain 1869-1940; politician; BBC broadcast;
RP08: Sir Richard Paget 1869-1955; barrister, scientist, British Deaf Association; no recording available, vowel diagram reconstructed from published sources
RP01: William Somerset Maugham 1874-1965; author; adopted RP (first language French); a recorded interview
RP07: Daniel Jones 1881-1967; phonetician, professor; educational material on gramophone record
RP02; Harold MacMillan 1894-1986; Earl of Stockton; politician; broadcast speech

This is essentially the RP described by Henry Sweet (1877) and Daniel Jones (1932). But the accent was already undergoing change before and during this period, although not always recognised until later in the 20th century.

Henry Sweet. 1877. Handbook of Phonetics. London, Macmillan.
Jones, Daniel. 1932. An Outline of English Phonetics. Leipzig, Teubner. 3rd edition.

One 19th century RP sound change is already beyond the horizon. Earlier RP had been rhotic. Non-rhotic RP appeared by 1800, the prescriptive debate for and against it continuing to about 1850 (Mugglestone 2003). Daniel Jones probably never heard rhotic RP, but Ellis and Sweet must have heard it. Rhotic RP had disappeared before it could be recorded,  so we can only try to imagine what it sounded like. Wells (1982) reports that the [ə]-like dipthong endings of NEAR, SQUARE, CURE etc. are now changing or disappearing. This [ə] element is the last vestige of rhoticity and is a worthy topic in itself and is not included here.

Mugglestone, Lynda. 2003. Talking Proper. Oxford, OUP.
Wells, J. C. 1982. Accents of English. Cambridge, CUP. Vol. 2.

The following selection of monophthong sound changes are included here:

  1. RP STRUT was formerly [ʌ], nowadays [a]. Fabricius (2007) studied this sound change in a set of published data from RP speakers born in the first half of the 20th century, and concluded it was complete by 1900 (everyone in her corpus had the new STRUT). However, Daniel Jones and Gimson (1962) described only the earlier [ʌ]-like variety (“fronted unrounded [ɔ]”). They both described open [a] for STRUT as regional in Southern England or London and not to be recommended.
  2. RP TRAP was formerly close to DRESS at IPA [æ] (accompanied by compression of DRESS and KIT towards FLEECE), but is now an open [ae] (with DRESS and KIT spread out). This change was not reported by Jones or Gimson (although Gimson recognised it as regional Southern). It was not reported until relatively recently (Wells 1982, Bauer 1985, Detterding 1997), although it can be seen in Wells’ data (1962). Fabricius found that this change was already in progress in the early decades of the 20th century, her oldest example born in 1900.
  3. RP THOUGHT is described by Jones and Gimson as [ɔː]. But Gimson also reported a possible on-going sound change to [oː], supported by Wells (1982). This turns out to be rare in RP, the often-quoted example being HM Queen Elizabeth (Harrington et al. 2000).
  4. RP GOOSE had a relatively dark timbre, although Jones noted an advanced variety following /j/, while Gimson noted increasing centralization. Henton (1983) reported higher instances of F2 since Wells (1962). Harrington et al. (2011) noted that part of the F2 increase was due to weaker lip-rounding.
Fabricius, Anne H. 2007. Variation and change in the TRAP and STRUT vowels of RP: a real time comparison of five acoustic data sets. Journal of the International Phonetic Association 37:293-320.
Gimson, A. C. 1962. An Introduction to the Pronunciation of English. London, Arnold.
Bauer, Laurie. 1985. Tracing phonetic change in the received pronunciation of British English. Journal of Phonetics 13:61-81.
Deterding, David. 1997. The formants of monophthong vowels in Standard Southern British Pronunciation. Journal of the International Phonetic Association 27:47-55.
Wells, J. C. 1962. A Study of the Formants of the Pure Vowels of British English. MA thesis, University of London.
Harrington, J., S. Palethorpe & C. Watson. 2000. Monophthongal vowel changes in Received Pronunciation. Journal of the International Phonetic Association 30:63-78.
Henton, C. 1983. Changes in the vowels of Received Pronunciation. Journal of Phonetics 11:353-371.
Harrington, J. S., F. Kleber & U. Reinhold. 2011. The contributions of the lips and tongue to the diachronic fronting of high back vowels in Standard Southern British English. Journal of the International Phonetic Association 41:137-156.

All the recordings have been subjected to lossy MP3 compression at some time during their lives. They were analysed using Praat, by LPC formant tracking where possible, by measuring directly on the spectrogram where that failed, or by measuring formant peaks on FFT slices. Some lower back vowels had to be abandoned and there are consequently fewer instances of FOOT, THOUGHT or LOT in some cases. Vowel formant frequencies were collected from fully focused syllables, to minimize spectral variation due to vowel reduction. Vowels were sampled at the moment where vowel articulation was least affected by surrounding consonant articulations, selected by comparing VC and CV formant transitions, to minimize spectral variation due to coarticulation.

Figure 1. F1/F2 diagram for RP12 Robert Baden-Powell.
Figure 2. F1/F2 diagram for RP06 Stanley Baldwin.

Figure 3: F1/F2 diagram for RP13 Neville Chamberlain

Figure 4. F1/F2 diagram for RP08 Sir Richard Paget, based
on data in his Human Speech, 1930, London, Kegan Paul
(formants reported as frequency ranges).

Figure 5. F1/F2 diagram for RP01 W. Somerset Maugham.
Figure 6. F1/F2 diagram for RP07 Daniel Jones, combined
from an educational recording (1929) and the commentary
to the 1956 cardinal vowel recording

Figure 7. F1/F2 diagram for RP02 Harold MacMillan.

Tongue height is interpreted as F1 on the vowel diagrams, tongue backing as F2 (explained here). Some of these examples had shorter than average vocal tracts with F2 reaching or approaching 2500Hz in FLEECE, and F1 extending beyond 800Hz. Most were spoken energetically with larger mouth openings so that F1 extended to 700-800Hz. An exception was Neville Chamberlain (Figure 3), whose F1 rarely reached 700Hz (except for BATH).

Open vowels are produced with a low pharyngeal constriction, with F1 higher than about 600-650Hz for most men, and higher for women and children (explained here). Neville Chamberlain’s open vowel limit was lowered to at least 550Hz due to his less energetic articulation.


All these examples have an open STRUT, demonstrating that the sound change from [ʌ] to [a] was complete in this group and must have occurred in the 1850s at the latest, or some time before 1850.

Occasionally STRUT is [ɑ]-like rather than [a]-like, identical with BATH. An example among these speakers is Harrold MacMillan (Figure 7).

Listen to the [a]-like RP STRUT by Robert Baden-Powell:
“brother other money comes comes up others”

Listen to the [a]-like STRUT by Stanley Baldwin:
“country government courage trust suffering”

Listen to the [a]-like STRUT by Neville Chamberlain
“government once country done up done trusted country”

Listen to the [a]-like STRUT by W. Somerset Maugham:
“sometimes one sh(r)ug”

Listen to the [a]-like STRUT by Daniel Jones:
up luggage tugs thunder luggage”

Listen to the [ɑ]-like STRUT by Harold MacMillan:
“hundred just country country but hundreds”


Only Neville Chamberlain (Figure 3) had the earlier closer TRAP along with compression of DRESS and KIT towards FLEECE. His F1 centre of gravity for TRAP was about 500-600Hz, where the other examples had their DRESS zone. And yet he also had occasional instances of open TRAP with F1>600Hz.

Additionally, W. Somerset Maugham and Harold MacMillan (Figures 4, 7) had their TRAP zones very close to DRESS but without compressing DRESS and KIT.

All the others had open TRAP with F1 at 650-800Hz, indicating that this sound change was already in progress by the 1850s.

The open [æ]-like timbre is produced with a maximally wide low pharyngeal constriction (cross section in the constriction > and a large mouth opening, yielding F1>600Hz and F2>1600Hz. A smaller mouth opening for a close TRAP lowers F1 towards 500Hz, compromising DRESS and leading to the compression of DRESS and KIT towards FLEECE. The sound change meant that new generations stopped using the smaller mouth openings for TRAP, limiting F1>600HZ. This demonstrates there is one [æ]-like zone that can be reached from a maximally wide low pharyngeal constriction. Smaller mouth openings add a hint of [ɛ] to the timbre, yielding the closer IPA [æ], while larger mouth openings limit F1, yielding open [æ]. This is why Neville Chamberlain could produce the closer IPA [æ] most of the time, but occasionally also had instances of open [æ].

Listen to closer TRAP by Neville Chamberlain, arranged from high F1 to low F1 (from open [æ] to close [æ]):
“factories plans bad attack ambassador handed practice cabinet man plans”

Listen to TRAP close to DRESS (F1 590-690Hz) by W. Somerset Maugham:
(“happened characters fact back pattern gathered”)

Listen to TRAP close to DRESS (F1 600-660Hz) by Harold MacMillan:
Africa Africa Africa travel”

Listen to open TRAP by Robert Baden-Powell:
“that carry travelling had happiness that happiness glad happy”

Listen to open TRAP by Stanley Baldwin:
“national crash stands tax balance”

Listen to open TRAP by Daniel Jones:
“back stand handling dashing gangways”


All these examples had RP [ɔː] for THOUGHT with F1 around 450-550Hz or higher. None of them consistently had [oː] for THOUGHT. This sound change does not appear to have commenced in RP during this period before 1900. However, 5 out of 8 regional Kentish rural informants had acquired this same sound change in this same period. By the 20th century this regional sound change was spreading through the home counties and beyond into the south west.


All these examples had F2 for GOOSE between about 800 and 1300Hz (Neville Chamberlain had one instance at 1500Hz, Figure 3). Assuming this RP F2 range represents Daniel Jones’ “advanced variety” there is nothing remarkable or unexpected here. In contrast, most of the regional Kentish informants had F2 for GOOSE extending to 1700Hz or beyond, underlining the 19th century RP preference for darker [u] timbres. Nor was Daniel Jones entirely correct regarding the nature of his advanced variety. He believed completely in the Bell vowel model, and trusted that shifting an [u]-like timbre towards [i] was due to advancing the tongue body. However, Harrington et al. (2011) demonstrated that weakening lip rounding would have the same effect. Again, Wood (1986) and Wood & Pettersson (1988) demonstrated that tongue blade elevation would also have the same effect (several of these instances of higher F2 for GOOSE were combinations of coronal+/uː/).  Finally, in the particular case of /j/+/uː/, the tongue body sweeps along the palate from [i] to the velar constriction for [u]. If this transition is broken off early, the higher F2 will also result, sometimes a very early break indeed resulting in F2 near 2000Hz. But not in 19th century RP, only in the emerging regional Home Counties SBE as yet.

Wood, Sidney. 1986. The acoustical significance of tongue, lip and larynx maneuvers in rounded palatal vowels. Journal of the Acoustical Society of America 80, 391-401.
Wood, Sidney & Thore Pettersson. 1988. Vowel reduction in Bulgarian; phonetic data and model experiments. Folia Linguistica 22, 239-262.

In conclusion, picking seven RP speakers at random, born in the second half of the 19th century, reveals that the STRUT change was complete by 1850 and the TRAP change was apparently already in progress. This particular sample included just one clear example with the earlier close TRAP, with DRESS and KIT compressed towards FLEECE, and yet even he had a mix of close and open TRAP. This is a remarkable, and presumably controversial, result.



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