Sound change in RP 1901-1925: TRAP

Seven examples of 20th century RP (born 1901-1925) are examined for signs of some reported sound changes to RP TRAP. This post follows on from the similar study for 19th century RP.

RP TRAP was formerly close to DRESS at the closer IPA [æ] (accompanied by compression of DRESS and KIT towards FLEECE), but is now an open [ae] (with DRESS and KIT spread out). Daniel Jones (1932) and Gimson (1962) described only the earlier version. Wells (1982) transcribes the new open TRAP as [a], the frontmost open vowel offered by Jones’ (and the IPA’s) vowel diagrams (see also here). Fabricius (2007) found that this change was already in progress in the early decades of the 20th century, both forms continuing side by side. Her oldest example was born in 1900, implying this sound change may have commenced before that. Of the seven 19th century examples in the previous post, just one had the older closer TRAP with DRESS and KIT compressed towards FLEECE, while all the others had the new open TRAP. It was concluded that this sound change had commenced in RP at least by 1850. Based on both sources of evidence, these RP examples born in 1901-1925 are expected to include both forms.

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. An Outline of English Phonetics. Leipzig, Teubner. 3rd edition.
Wells, J. C. 1982. Accents of English. Cambridge, CUP. Vol. 2.

Speakers born in 1901-1910:

Figure 1. F1/F2 diagram for RP14 born 1901-1910; the arrow
shows one instance of an [ɛæ]-like diphthong for TRAP.

Figure 2. F1/F2 diagram for RP15 born 1901-1910; the arrow
shows one instance of an [ɛæ]-like diphthong for TRAP.

Figure 3. F1/F2 diagram for RP03 born 1901-1910. Recording (a).

Figure 4. F1/F2 diagram for RP03 born 1901-1910.
Recording (b) five years later than Figure 3.

Speakers born in 1911-1920:

Figure 5. F1/F2 diagram for RP16 born in 1911-1920.

Figure 6. F1/F2 diagram for RP17 born 1911-1920; the arrow
shows one instance of an [ɛæ]-like diphthong for TRAP.

Speakers born in 1921-1925:

Figure 7. F1/F2 diagram for RP04 born 1921-1925.

Figure 8. F1/F2 diagram for RP018 born 1921-1925.

General comments on Figures 1-8

There are two recordings for RP03 (Figures 3-4) made five years apart. They are very similar.

All seven are definitely examples of RP (LOT is [ɒ] partly overlapping BATH or very close to it, while THOUGHT is [ɔː], but see also the discussion on THOUGHT). There is no other accent of British English that has this particular combination of vowel timbres for LOT and THOUGHT.


One of these seven examples had the earlier closer TRAP complete with compression of DRESS and KIT towards FLEECE. This was RP15, Figure 2. The evidence of these diagrams is that F1 for compressed DRESS is usually about 400-500Hz, so that the FLEECE-DRESS F1 range is shortened to about 250Hz. In contrast, F1 for uncompressed DRESS is about 500-600Hz and the FLEECE-DRESS F1 range is larger, about 350Hz. Previously, in the 19th century group, there was one example who fulfilled all the criteria for closer TRAP. Like him, this example also had both closer instances of TRAP with F1 roughly 500-600Hz and open instances with F1>600Hz. Additionally, three had occasional instances of a diphthong [ɛæ], not previously found in the 19th century group. This diphthong was never mentioned by Jones, but it is described by Wells (1982, vol. 2). The three examples are RP15 (Figure 2, together with close TRAP) and RP14 and RP17 (Figures 1, 6) with open TRAP. There was no obvious systematic rule in this 1901-1925 group for producing a diphthong or a monophthong.

The other six examples had open TRAP, with F1>600Hz.

Listen to close TRAP by RP15 (Figure 2), ordered by rising F1 from close to open [æ]:
Close [æ]: “Cavendish mathematics natural scattering sabbatical mechanics”;
Open [æ] “that planet hand”

Listen to open TRAP by RP14 (Figure 1):
“fascinated natural patchy packed pack family understand”

Listen to open TRAP by RP03 (Figure 4):
“background valuable man fashion fantastic passage fascinating”

Listen to open TRAP by RP16 (Figure 5):
“family caterpillar enthusiastc accident perhaps badly”

Listen to open TRAP by RP04 (Figure 7):
“characters admirable attitudes chat acts”

Listen to open TRAP by RP18 (Figure 8):
“back fact fact accurate galaxies”