Sound change in 19th century RP: STRUT

Seven speakers of RP born in the latter half of the 19th century are examined for signs of a reported sound change to STRUT. They are described here.

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 peripheral STRUT). However, Daniel Jones (1932) still described only the earlier [ʌ]-like variety (“fronted unrounded [ɔ]”). In late editions (1950s or 1960s) he noted that [a]-like and [ɑ]-like variants also occurred. Gimson (1962) noted that the pronunciation [ʌ] had changed to centralized and raised [a] (he wrote [ä]) except in conservative RP. Gimson did not mention an [ɑ]-like variant in (1962). Wells (1982 §4.1.7) noted that “fronted realizations of /ʌ/” had existed in RP for rather longer than the 1960s or 1970s.

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.
Jones, Daniel. 1932. Outline of English Phonetics. Leipzig, Teubner. 3rd revised edition.
Wells, John C. 1982. Accents of English. Cambridge University Press. Vol. 2.

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. This includes Daniel Jones too, who had always taught that his own pronunciation was [ʌ].

Occasionally STRUT is [ɑ]-like rather than [a]-like, identical with BATH. An example among these speakers is Harold MacMillan (Figure 7), confirming Jones’ late amendment.

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”

In conclusion, picking seven RP speakers at random, born in the second half of the 19th century, reveals that all had the new STRUT change, suggesting it might have been complete by 1850, or at least had commenced by then. This includes Daniel Jones who always described it as [ʌ].