# Live or leave! Vowel quality and vowel length in the intelligibility of advanced Spanish-accented English

Mateusz Pietraszek

► To cite this version:

Mateusz Pietraszek. Live or leave! Vowel quality and vowel length in the intelligibility of advanced Spanish-accented English. In A. Kirkova-Naskova, P. Humanez-Berral & A. Henderson, (Eds.). Proceedings of the 8th International Conference on English Pronunciation: Issues and Practices, Université Grenoble-Alpes, pp.71-83, 2025, 10.5281/zenodo.16696002/. hal-05196467

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# Live or leave! Vowel quality and vowel length in the intelligibility of advanced Spanish-accented English

Mateusz Pietraszek

Complutense University of Madrid

## Abstract

Often characterised as short and long in both research and teaching practice (Cruttenden, 2008; Hancock, 2012, Walker, 2010), the KIT and FLEECE vowels are commonly confused by Spanish learners of English as their mother tongue lacks a similar distinction (RAE, 2011). Length is also traditionally insisted upon in instruction and even more recent intelligibility-based (Levis, 2005) approaches to international English (Jenkins, 2000; Walker, 2010) advocate its importance prioritising it over vowel quality. The goal of this paper is to examine the role of vowel length and quality in Spanish-accented English from a quantitative and qualitative exploratory perspective. Sixty advanced English speakers with L1 Spanish were recorded and the acoustic properties of their FLEECE and KIT vowels were analysed in the words *live* and *leave*. The overall intelligibility (Kang et al., 2018; Wang, 2007), comprehensibility, and foreign-accentedness (Derwing & Munro, 1997, 2015) of the participants’ speech were assessed online by an international sample of 330 listeners from 28 L1 backgrounds. No association was detected between the overall pronunciation scores and vowel length. However, some evidence suggested that distinguishing at least one formant might be associated with increased comprehensibility and decreased accentedness. Additionally, the analysis of phonological intelligibility breakdowns showed that these could only be explained with a reference to formant values but not length distinctions. Thus, it is argued that vowel length in KIT and FLEECE may be disregarded and the focus in receptive and productive instruction should be on quality distinctions.

**Keywords:** accentedness, intelligibility, vowel length, vowel quality

<figure><img src="image_2.png" /></figure>
# 1. Introduction

The English *FLEECE* /i:/ and *KIT* /i/ vowels are most often characterised as long and short segments in both dictionaries and learning materials for L2 English students (Cruttenden, 2008; Hancock, 2012; Wells, 2008), especially – but not exclusively – those teaching British English. In educational contexts, this might lead to the conclusion that contrasting these vowels mainly based on length is sufficient in order to tease them apart, as isolated drills very often focus on length as the most integral feature to be trained when contrasting those vowels (see Mompeán-González, 2001). However, this simplistic assumption poses several problems aggravated by the very fact that vowel length is a relative phenomenon. Firstly, the *FLEECE* and *KIT* vowels have different articulations regardless of their length, the latter being both more open and back than the former.<fnref n="1" /> Secondly, analyses of Standard Southern British English (Lindsey, 2019; Wells, 1982) and General American (Celce Murcia et al., 2010) tend to describe the *FLEECE* vowel as a diphthong [ij], which glides from a more open and centralised articulation towards a higher and fronter point of articulation. Thirdly, vowel length in English is context-dependent (Ladefoged, 2001; Odden, 2011) and it is commonly used as a cue regarding the voicing of the following consonant (Rojczyk, 2010) or even the preceding consonant (Viswanathan et al., 2020) by native speakers of English. As a result of pre-fortis clipping (Roach, 2009), long vowels may even be pronounced shorter than short vowels, e.g., when comparing a long vowel before a voiceless stop with a short vowel before a long one. Length also varies depending on the number of syllables in a word (Ladefoged, 2001), hence the first syllable of *reading* will be shorter than the word *read* in the same context. Finally, perceptual studies suggest length is insufficient when distinguishing vowel qualities among native speakers (Hillenbrand, 1995; Liu et al, 2014).

It is therefore evident that vowels are never distinguished by length alone in English, and the descriptions of some varieties of English – including the most widely spoken, General American – make no reference to length as a relevant vowel feature (see Avery & Ehrlich, 1992). However, even relatively recent teaching recommendations – in all likelihood encouraged by canonical phonemic transcription in dictionaries (Wells, 2008) – insist on preserving length contrasts. Not only do they posit length as a feature necessary for internationally intelligible English, but they may even prioritise it over quality distinctions. This is the case, for example, of the Lingua Franca Core of features necessary for international communication in English as a global language (Jenkins, 2000, 2002; Walker, 2010). However, many languages do not have phonological length distinctions whereas all languages, including English and Spanish, distinguish between vowel qualities, which might be sufficient for basic vowel distinctions in English as an international language. In the particular case of Spanish, although vowel length differences exist in the language (Marín Gálvez, 1994), their phonological functions are not comparable to those in English (Fox et al., 1995). This feature, coupled with the fact that Spanish only has one high front vowel /i/, indeed poses pronunciation problems for L1-Spanish speakers of English (Finch & Ortiz Lira, 1982; Gómez-González & Sánchez-Roura 2016; Hancock, 2012; Walker, 2010). Previous studies have shown that, unlike English native speakers, Spanish speakers are largely insensitive to length differences (Fox et al., 1995; Viswanathan et al., 2020) or that their sensitivity to duration is lower than that of native speakers (Kondaurova & Francis, 2008). Other evidence suggests that instruction practices may lead Spanish speakers to rely on length even more than native speakers do in discrimination tasks (Mompeán-González, 2001). Finally, regarding international

<footnote n="1">¹ See Durand (2005) for a comprehensive summary of the debate on the relevance of vowel length and quality in English phonology.</footnote>
intelligibility, the evidence in support of length distinctions to preserve intelligibility has so far
been scarce and inconclusive (Jurado-Bravo, 2018).

**1.1 Aims and research questions**

The main goal of this exploratory study is to examine the utility of insisting on length versus
quality distinctions in teaching the FLEECE : KIT contrast in Peninsular Spanish, applying the
intelligibility principle (Levis, 2005) in English as an international lingua franca (Jenkins,
2000). With this aim in mind, the following research questions (RQ) will be addressed:

RQ1: Do Spanish speakers of English in the sample produce the FLEECE and KIT vowels with different length and/or quality?

RQ2: Is a contrast between FLEECE and KIT in L2 English associated with improved general pronunciation performance scores?

RQ3: What phonological intelligibility breakdowns may occur when FLEECE and KIT vowels are mispronounced?

**2. Methodology**

**2.1 Participants, recordings, and scoring**

This mixed-methods (Creswell et al., 2008) exploratory study is part of a broader research
project (Pietraszek, 2024a, Pietraszek, 2024b). The sample consisted of 60 university students
(26 females and 34 males; aged 19–26, M = 21.2) majoring in disciplines unrelated to
linguistics and having B2–C2 levels of English proficiency. The speakers were recorded using
a set of semantically unpredictable sentences (SUS) (Benoît et al., 1996; Pietraszek, 2024a)
and an elicitation paragraph (Pietraszek, 2024b). SUS were selected as the best instrument to
test phonemic intelligibility, because most semantic information is eliminated (Benoît et al.,
1996; Kang et al., 2018). Subsequently, 330 international listeners with 28 different L1s
evaluated the speakers’ comprehensibility and foreign-accentedness, and transcribed their SUS
for intelligibility measurements. The *comprehensibility* (COM) and *foreign-accentedness* (FA)
(Derwing & Munro, 1997, 2015) scores are averaged ratings the speakers received from the
listeners on a 1–6 semantic differential scale using excerpts from the paragraph (Pietraszek,
2024b). *Intelligibility* (INT) was operationalised as phonological utterance decoding at the
segmental level (cf. Jenkins, 2000; Kang et al., 2018). Thus, the INT score was calculated as a
mean score based on the number of words correctly interpreted by the listeners in the test
following a specially designed protocol (Pietraszek, 2024a). Similarly, the qualitative part of
the study, i.e., intelligibility breakdown analysis, is based on listener transcriptions of SUS in
the online test (Pietraszek, 2024a).

**2.2 Acoustic analyses**

The acoustic analyses are based on two words extracted from two syntactically comparable
SUS: *live* for the KIT vowel and *leave* for the FLEECE vowel. The vowel length of the LIVE and
LEAVE vowels was measured for each speaker using Praat (Boersma & Weenink, 2019). As
“the lengths of segments depend on their position in the word, their position in the phrase and
the whole utterance, where the stresses occur in the utterance, and many other factors”
(Ladefoged, 2003, p. 102), in order for the measurements to be comparable, the instances were
taken from SUS number 3 and 4 in series 3 for the minimal pair *leave–live*, i.e., *Leave the sport*
*and the thought* and *Live the sport and the fund*. The fact that the vowels came from two
consecutive sentences ensured a relatively stable pace of speech per speaker. Additionally, the syntactic position of both words was the same, in order to minimise contextual, phonotactic influence on vowel length. The exact procedure and the selection of starting and ending points in length measurements was particularly important owing to the phonological context of the targeted vowels. These were situated between a lateral approximant and a fricative, whose boundaries are more fluid than those of plosives, for example, as both laterals and fricatives are closer to vowels on the sonority scale (see Cruttenden, 2008). The boundaries were set using a spectrogram (see Figure 1) showing the intensity of vowel formants. The length was extracted using the accompanying waveform (see Figure 2) by selecting the first valley and the

<caption>**Figure 1**</caption>

*Spectrogram for /li:v/.*

<figure><img src="image_3.png" /><figcaption>**Figure 2**</figcaption></figure>

*Oscillogram for /li:v/.*

<figure><img src="image_4.png" /></figure>
last peak corresponding to the points previously established on the spectrogram. The beginning and the end of the vowel were established at the boundaries of the area where F1 and F2 remained relatively stable. The values of F1 and F2 were registered for each vowel, except for one speaker for whom it was impossible to establish F2 values in a reliable fashion using Praat.

Given the potential inter-speaker differences, the variation in length was calculated as individual ratios of long to short vowel. The break-off point for considering the existence of a length distinction was a long-to-short vowel duration ratio of 1.25 (i.e., a long vowel, which is at least 25% longer than its short counterpart). The ratio was based on previous studies of British and American English, in particular, Cruttenden's (2008, p. 95) figures return a 1.85 ratio, similar to Wells' (1962) 1.9 average ratio. However, some studies of US English report much smaller differences (ratios), e.g., 1.23 in Liu et al. (2014, p. 243) and 1.28 in Hillenbrand et al. (1995, p. 3103). Given that research suggests that native speakers of General American may present truly short length differences in their vowels, a conservatively small ratio was chosen for this study as it would be unreasonable to set the bar higher for international English speakers than for native speakers.

Similarly, the differences in F1 and F2 were calculated for every speaker. Significant formant difference values were established at 70 Hz for F1 and 300 Hz for F2 upon consulting mean differences in formant measurements presented in Cruttenden (2008) (for RP), Ferragne and Pellegrino (2010) for Standard Southern English, London, and Hillenbrand et al. (1995) for General American English (see Table 1). The mean difference in F1 (at 82 Hz) and F2 (at 381 Hz) was considered alongside the minimum registered values. As in the case of length, it would not be reasonable to require international English speakers to produce contrasts larger than those of NSs.

<caption>**Table 1**</caption>

*F1 and F2 Values and Differences in FLEECE and KIT (in Hertz)*

<table><thead><tr><th>Study</th><th>Vowel</th><th>F1</th><th>F2</th><th colspan="2">DIFFERENCE</th></tr></thead><tbody><tr><td rowspan="2">Cruttenden 2008<br>British English (RP)</td><td>FLEECE</td><td><i>M</i> 280<br><i>F</i> 303</td><td><i>M</i> 2249<br><i>F</i> 2654</td><td>F1</td><td><i>M</i> 87<br><i>F</i> 81</td></tr><tr><td>KIT</td><td><i>M</i> 367<br><i>F</i> 384</td><td><i>M</i> 1757<br><i>F</i> 2174</td><td>F2</td><td><i>M</i> 492<br><i>F</i> 480</td></tr><tr><td rowspan="2">Ferragne & Pellegrino<br>2010<br>Standard Southern<br>English (SSE)</td><td>FLEECE</td><td>273</td><td>2289</td><td>F1</td><td>113</td></tr><tr><td>KIT</td><td>386</td><td>2038</td><td>F2</td><td>251</td></tr><tr><td rowspan="2">Hildebrand et al 1995<br>General American<br>(GenAm)</td><td>FLEECE</td><td><i>M</i> 342<br><i>F</i> 437</td><td><i>M</i> 2322<br><i>F</i> 2761</td><td>F1</td><td><i>M</i> 85<br><i>F</i> 46</td></tr><tr><td>KIT</td><td><i>M</i> 427<br><i>F</i> 483</td><td><i>M</i> 2034<br><i>F</i> 2365</td><td>F2</td><td><i>M</i> 288<br><i>F</i> 396</td></tr></tbody></table>

*Note.* *M* = Male, *F* = Female
# 3. Results and discussion

## 3.1 Exploratory quantitative analysis

The results presented in this section address research questions 1 (RQ1) and 2 (RQ2). As previously mentioned, due to speech rate differences, what was deemed relevant was the relative difference in the length of the two vowels in two, consecutive SUS for each speaker and not the absolute length values in milliseconds (see Hisagi et al., 2024; Peterson & Lehiste, 1960; Wells, 1962). The absolute values and the ratios are shown in Figure 3 below. The data show that the length of KIT was slightly shorter than that of FLEECE. This difference was also statistically significant ($t(58) = 2.365, p = .022$). However, the effect size ($d = .226$) was very small reaching non-existent sensu Cohen (1988)<fnref n="2" />. More importantly, 71% of the speakers did not produce length distinctions.

<caption>Figure 3</caption>

FLEECE and KIT Vowel Length

<figure><img src="image_5.png" /></figure>

<table><thead><tr><th></th><th>N</th><th>Min</th><th>Max</th><th>Mean</th><th>SD</th></tr></thead><tbody><tr><td>/i:/</td><td>59</td><td>27 ms</td><td>141 ms</td><td>79 ms</td><td>23 ms</td></tr><tr><td>/ɪ/</td><td>59</td><td>25 ms</td><td>150 ms</td><td>73 ms</td><td>22 ms</td></tr><tr><td>Long : Short Ratio</td><td>59</td><td>.46</td><td>2.3</td><td>1.15</td><td>0.46</td></tr></tbody></table>

Regarding vowel quality, the data in Figure 4 show that the mean formant values for both vowels were similar. Although paired sample t-tests show significant differences for F1 ($t(58) = -3.375, p = .001, d = -.339$) and for F2 ($t(57) = 2.452, p = .017, d = .171$) between the two

<footnote n="2">² d < .2 NO EFFECT; d ≥ .2 SMALL EFFECT; d ≥ .5 MEDIUM EFFECT; d ≥ .8 LARGE EFFECT.</footnote>
vowels, the effect sizes are fairly small in the case of F1, and below the threshold of any noticeable difference for F2 (Cohen, 1988).

<caption>Figure 4</caption>

FLEECE and KIT Vowel Formants (F1 and F2)

<figure><img src="image_6.png" /></figure>

<table><thead><tr><th></th><th></th><th>N</th><th>Min</th><th>Max</th><th>M</th><th>SD</th></tr></thead><tbody><tr><td rowspan="2">F1</td><td>/i:/</td><td>59</td><td>224</td><td>491</td><td>333</td><td>51</td></tr><tr><td>/ɪ/</td><td>59</td><td>258</td><td>509</td><td>357</td><td>51</td></tr><tr><td rowspan="2">F1 difference<br>KIT-FLEECE</td><td></td><td>59</td><td>-87</td><td>240</td><td>24</td><td>55</td></tr><tr><td>/i:/</td><td>58</td><td>1644</td><td>2712</td><td>2163</td><td>254</td></tr><tr><td rowspan="2">F2</td><td>/i:/</td><td>58</td><td>1604</td><td>2680</td><td>2100</td><td>264</td></tr><tr><td>/ɪ/</td><td>58</td><td>-622</td><td>629</td><td>63</td><td>194</td></tr><tr><td colspan="2">F2 difference<br>FLEECE-KIT</td><td>58</td><td>-622</td><td>629</td><td>63</td><td>194</td></tr></tbody></table>

F1 was different in seven students out of 59 (12%), while F2 was distinguished by five out of 58 (8.6%). However, only four out of 58 speakers (6.9%) distinguished both. Hence, the data reveal that the majority of the sampled speakers did not make length or quality distinctions when producing the FLEECE and KIT vowels (RQ1).

With regard to RQ2, no differences were detected in the pronunciation performance scores between those who did and did not make length distinctions.<fnref n="3" /> Similarly, no significant correlations were found between the FLEECE-to-KIT length ratio and the variables of COM/FA/INT<fnref n="4" />.

<footnote n="3">³ COM *t*(57) = -.199, *p* = .843; FA *t*(57) = .811, *p* = .421; INT *t*(57) = -.677, *p* = .101.</footnote>

<footnote n="4">⁴ Correlations between length ratio and (a) COM: *r* = .056, *p* = .675, (b) FA: *r* = -.122, *p* = .359, (c) INT: *r* = -.171, (d) *p* = .195.</footnote>
In the case of quality, as very few students actually presented formant distinctions meeting the pre-established – already fairly lenient – criteria, in order to determine whether there was any association between the overall pronunciation performance and vowel quality, participants were split into two groups: those who make a distinction in at least one formant (n = 9) and those who do not distinguish any of them (n = 49). Subsequently, tests were carried out to detect potential differences between group A (at least one formant different) and group B (no quality distinction).

The results showed that group A (M = 4.8, Mdn = 5, SD = .5) was more comprehensible than group B (M = 3.93, Mdn = 4.07, SD = 6.67), U = 395, r = .45, p = .001. Similarly, group A (M = 3.08, Mdn = 3.29, SD = .79) was less accented than group B (M = 4.31, Mdn = 4.35, SD = .74), U = 44, r = -.50, p = .001. However, there were no significant differences in intelligibility, U = 304, p = .096. These findings indicate that those who make a noticeable distinction between the two vowels are evaluated as subjectively less accented and more comprehensible. This certainly reflects the influence of other pronunciation features, as the COM-FA-INT measures are general ratings. However, the results indicate that the speakers who are rated more favourably are more likely to make formant distinctions, but not necessarily length distinctions.

## 3.2 Qualitative analysis of intelligibility breakdowns

The data presented in Table 3 answer RQ3, showcasing what potential intelligibility breakdowns may occur when the FLEECE and KIT phonemes are mispronounced and how they may be interpreted as a result. Table 2 below presents all the cases where there were noticeable divergences in the interpretations given by the listeners on the test or between the intended speaker output and listener input. We can see that the listeners had to rely mainly on qualitative information due to the apparent lack of length differences. Similarly, diphthongal [ij] pronunciations of the FLEECE vowel were not detected in the Spanish-accented sample. Although it is difficult to detect a clear pattern, what is certain is that in most cases, the problematic vowel was the lax vowel /ɪ/ in *live* or *list* when pronounced as [i] (e.g., in S20), which was normally interpreted as /i:/.

Yet a correct lax pronunciation did not always guarantee correct understanding as it was still misinterpreted by half of the listeners in S40 and 64% in S30. In almost all cases, except for S29, the interpretation was in favour of /i:/ regardless of the actual input. As no length distinctions were detected and most vowels in the corpus were short, given that /ɪ/ is in fact a short vowel and it was still interpreted as the long /i:/, length does not seem to be the decisive factor for the international listeners; the latter favour vowel quality with a certain preference for /i:/ when in doubt. Previous research has shown that increased length may, paradoxically, also lead to a higher number of wrong interpretations of the FLEECE vowel (Jurado-Bravo, 2018).

Concerning the contrast between /ɪ/ (the KIT vowel) and /i:/ (the FLEECE vowel), it sometimes proved difficult to determine which vowel was pronounced and thus the transcriptions in Table 3 should not be considered absolutely reliable although they were computer assisted. Depending on the dialect, there may also exist at least some overlapping between the exact formants of both vowels, considering the tense quality of the vowel /ɪ/ in Australian English or the fact that /i:/ is commonly diphthongised to [ij], [ii] or even [i:j] (Wells, 1982, pp. 127, 140). Post-hoc acoustic analyses compared the formants in two sets of words: 1) S30, S40, S20, and 2) S29 vs S59 from Table 3. Additionally, a pair of control items were chosen from the corpus and S20 for *live*, S09 for *list*. Length was also measured yet none of the speakers in question made significant length distinctions and thus, it will not be discussed here.
<caption>Table 2</caption>

KIT vowel /i/ and FLEECE Vowel /i:/ – Intelligibility Breakdowns

<table><thead><tr><th></th><th colspan="2">live [liv]</th><th colspan="2">leave [liv]</th><th colspan="2">list [list]</th></tr><tr><th></th><th>interpreted<br>as:</th><th>n</th><th>%</th><th>interpreted<br>as:</th><th>n</th><th>%</th></tr></thead><tbody><tr><td>/i:/ leave</td><td></td><td>42</td><td>98</td><td>/i:/ leave</td><td>21</td><td>78</td></tr><tr><td>/i/ live</td><td></td><td>1</td><td>2</td><td>/i/ live, this</td><td>6</td><td>22</td></tr><tr><td>Total</td><td></td><td>43</td><td>100</td><td>Total</td><td>27</td><td>100</td></tr><tr><td>S20 Live the sport and the fund.</td><td colspan="6">S23 Leave the sport and the thought.</td></tr><tr><td></td><td colspan="6">S29 Stop the stock and the list.</td></tr></tbody></table><table><thead><tr><th></th><th colspan="2">live [lif]</th><th colspan="2">leave [l1:d]</th><th colspan="2">live [liv]</th></tr><tr><th></th><th>interpreted<br>as:</th><th>n</th><th>%</th><th>interpreted<br>as:</th><th>n</th><th>%</th></tr></thead><tbody><tr><td>/i:/ leave</td><td></td><td>23</td><td>64</td><td>/i:/ leave</td><td>18</td><td>75</td></tr><tr><td>/i/ live</td><td></td><td>13</td><td>36</td><td>/i/ live, this</td><td>3</td><td>12.5</td></tr><tr><td>Total</td><td></td><td>36</td><td>100</td><td>/e1/ laid, late</td><td>3</td><td>12.5</td></tr><tr><td>S30 Live the sport and the fund.</td><td colspan="6">S33 Leave the sport and the thought.</td></tr><tr><td></td><td colspan="6">S40 Live the sport and the fund.</td></tr></tbody></table><table><thead><tr><th></th><th colspan="2">live [lif]</th><th colspan="2">list [list]</th><th colspan="2">live [liv]</th></tr><tr><th></th><th>interpreted<br>as:</th><th>n</th><th>%</th><th>interpreted<br>as:</th><th>n</th><th>%</th></tr></thead><tbody><tr><td>/i:/ leave</td><td></td><td>17</td><td>85</td><td>/i:/ list</td><td>14</td><td>61</td></tr><tr><td>/i/ live</td><td></td><td>3</td><td>15</td><td>/i/ least</td><td>9</td><td>39</td></tr><tr><td>Total</td><td></td><td>20</td><td>100</td><td>Total</td><td>23</td><td>100</td></tr><tr><td>S50 Live the sport and the fund.</td><td colspan="6">S59 Stop the stock and the list.</td></tr><tr><td></td><td colspan="6">S60 Live the sport and the fund.</td></tr></tbody></table>
<table><caption>**Table 3**</caption><caption>Formant Values For the KIT Vowel</caption><thead><tr><th></th><th>F1</th><th>F2</th><th>F2-F1</th><th>interpreted<br>as /i/</th></tr></thead><tbody><tr><td>S30 <i>live</i></td><td>331</td><td>1737</td><td>1406</td><td>36%</td></tr><tr><td>S40 <i>live</i></td><td>364</td><td>2179</td><td>1815</td><td>50%</td></tr><tr><td>S20 <i>live</i></td><td>336</td><td>2574</td><td>2238</td><td>2%</td></tr><tr><td>* S10 <i>live</i></td><td>438</td><td>2358</td><td>1920</td><td>40%</td></tr><tr><td>S29 <i>list</i></td><td>343</td><td>1855</td><td>1512</td><td>69%</td></tr><tr><td>S59 <i>list</i></td><td>347</td><td>2165</td><td>1818</td><td>39%</td></tr><tr><td>* S09 <i>list</i></td><td>421</td><td>2221</td><td>1800</td><td>90%</td></tr></tbody></table>

*Note. * = control items

Although the control items clearly have higher F1 values (suggesting a vowel more open than /i:/), only the vowel in *list* (S09) was actually interpreted correctly by most people. Thus, the table shows no observable patterns between the interpretations and the phonetic input at the formant level. One tentative explanation for better recognition of the vowel in *list* (S09) than the one in *live* (S10) is, again, the syntactic and lexical information. The latter is less likely to bear a direct object than the other member of the minimal pair *live-leave*, both of whose members are high-frequency verbs. Similarly, the correct interpretation of *list* may be due to the fact that a noun is much more likely to appear after the determiner *the* than the adverb or adjective *least*. The other analysed items seem to be harder to interpret, but there seems to be at least some evidence that higher F1 values (more than 400 Hz, indicating a more open vowel) were more often interpreted as /i/, although they may also have been repaired to /i:/ due to the limited, yet present, contextual information. On the other hand, a very high F2 (over 2500 Hz suggesting a more fronted vowel) was almost exclusively heard as /i:/ in conjunction with a low F1 value (S20) and a large F2-F1 difference (over 2200 Hz). This was not the case, however, when the F1 value was low but the F2 was not high enough (S30, S40, S29, S59), in which case /i/ was commonly interpreted as the vowel in *FLEECE*, although not always by the majority.

**4. Conclusions**

Most Spanish speakers in the sample made no length distinctions although they are likely to have been exposed to relevant pedagogical materials, for example minimal-pair length drills. Similarly, most of the speakers made no quality distinctions, often conflating the two phonemes. Although length distinctions were more prevalent in the sample than quality differences, it was the latter which were associated with better overall pronunciation performance scores suggesting that quality distinctions are a feature of more comprehensible, intelligible, and less accented speech. Most intelligibility breakdowns occurred because of substituting the *FLEECE* vowel for the one in *KIT*. The limited evidence also suggests that acoustic information regarding both F1 and F2 was used alongside the syntactic context provided by the SUS and that the vowel in *FLEECE* might be favoured even when *KIT* is pronounced.
While this exploratory research cannot reliably answer the question of whether length plays a role in international English intelligibility, it provides some evidence that changing the quality of a vowel may lead to misunderstandings. Thus, dismissing vowel quality as a core international English feature while insisting on length seems unfounded and therefore risky. It also places an additional burden on the learners who are asked to develop a phonological vowel category foreign to their linguistic system, while their target language uses it mainly as a marker of final consonant voicing. Thus, it seems reasonable, as a pedagogical implication of the results presented in this study, to raise learners' awareness of the varying duration due to fortis clipping regardless of the exact vowel quality, rather than to treat duration as the most relevant distinctive feature of the FLEECE and KIT phonemes.

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## About the author

Mateusz Pietraszek is an Assistant Professor at the Complutense University of Madrid. He holds a PhD in English Linguistics and an MA in Spanish Linguistics. He has been teaching English for Specific Purposes, General English, and English Phonetics and Phonology at the university level for 16 years. His research interests include English and Spanish phonetics (intelligibility, accent, and attitudes to pronunciation), English as a Lingua Franca (ELF), comparative morphosyntax, English-medium instruction (EMI), and higher education. A passionate language learner, he speaks seven languages (English, Spanish, Polish, French, Catalan, German, and Esperanto) and is a member of the International Hyperpolyglot Association (HYPIA).

Email: mpietras@ucm.es