Foreign Accent Syndrome and force of articulation

INTRODUCTION

Some neurological syndromes, such as the Foreign Accent Syndrome, appeal so much to the

imagination that newspapers report on the typical symptoms. These symptoms are often

exaggerated or misunderstood in the non-medical press. On September 3rd, 2013, the British

newspaper ‘Daily Mail’ published an article entitled: ‘The woman from Plymouth who woke up

with a Chinese accent’. In this article, a 38-year old woman was described who could not speak for

a while after a migraine insult. Later on, her speech developed into a ‘Chinese accent’. The

phenomenon that someone after brain damage speaks with a strange accent is called Foreign

Accent Syndrome (FAS).

FAS is an intriguing disorder, which was first described almost a century ago (Marie,

1907), yet it continues to be poorly understood. The FAS speaker’s inability to make phonetic and

phonemic contrasts of his native language results in a perceived foreign accent in listeners (Gurd,

Besel, Bladon, & Bamford, 1988; Takayama, Sugishita, Kido, Ogawa, & Akiguchi, 1993). The

number of cases published is restricted, around one hundred until now. This suggests that the

incidence is low. However, it may be that FAS largely escaped the attention of the research

community. This can be due to two reasons: First, FAS often occurs as a transient stage in

recovery or deterioration. Relatively few people have a persisting FAS. Next, in cases with a

persisting form, the accent is in general one of the only symptoms: intelligibility in daily living is

not or hardly affected. As such, speakers with FAS tend not to be referred to speech-language

therapists, and other physicians appear to assume there are no communication concerns.

However, many reports allude to marked psychosocial consequences of living with FAS (Miller,

2010).

The current study will describe a case study of a Dutch male with FAS, AA. We will try to

show that the foreign accent of AA is due to the fact that he speaks with much more force of

articulation than normal speakers of Dutch. Due to this force of articulation, characteristics of

different languages become apparent.

Characteristics of FAS

The distinct speech characteristics of FAS described in the literature mainly concern segmental

and prosodic deficits, although not necessarily both levels are affected. Among the segmental

characteristics, vowels are more vulnerable than consonants. The vowel anomalies have shown a

variety of patterns, including vowel tensing, and thus lack of vowel reduction in unstressed

syllables (Van Lancker, Bogen, & Canter, 1983; Whitaker, 1982; Blumstein, Alexander, Ryalls, Katz,

& Dworetzky, 1987; Ingram, McCormack & Kennedy, 1992), schwas becoming more like full

vowels, and monophthongisation of diphthongs, and a tendency towards fronting and raising

(Whitaker, 1982; Gurd et al., 1988; Dankovičová, Gurd, & Marshall, 2001; Dankovičová & Hunt,

2011). Other acoustic analyses, however, demonstrated an overall reduction in the acoustic vowel

space, due to a restricted F1 range (Ingram et al., 1992; Moonis et al., 1996). With respect to vowel

length, lengthening (Van Lancker et al., 1983; Graff-Radford, Cooper, Colsher, & Damasio,1986,

Ardila Roselli, & Ardila, 1988; Perkins, Ryalls, Carson, & Whiteside, 2010) as well as shortening

have been reported (Pick, 1919). Nevertheless, acoustic data of some individuals with FAS

showed normal vowel durations, although there is an overall greater variability in vowel formants

(Blumstein et al., 1987). Alterations of consonants are also mentioned in the literature, including

change of place of articulation and manner, and voicing errors (Whitaker, 1982; Ardila et al.,

1988; Gurd et al., 1988; Ingram et al., 1992).

In terms of prosodic characteristics, the feature most frequently reported in FAS cases is a

change in prosody, specifically a tendency towards ‘syllable-timing’ in languages where ‘stress-

timing’ is expected (e.g. Blumstein et al., 1987; Gurd, Coleman, Costello, & Marshall, 2001; Scott

Clegg, Rudge & Burgess, 2006; Haley, Roth, Helm-Estabrooks, & Thiessen, 2010). The perception

of a ‘syllable-timed’ rhythm can be due to a number of characteristics: unusual equal syllable

durations (isochronicity), for example, due to lack of vowel reduction (e.g. Whitaker, 1982) and

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the use of epenthetic vowels (Ardila et al., 1988; Ingram et al., 1992). A recent study of

Kuschmann and Lowit (2012) investigated intonation patterns to identify the characteristics that

were compromised in FAS to their ability to signal new and given information (information

status) within sentences. Results showed that speakers with FAS frequently place pitch accents on

given information instead of de-accenting these elements.

Characteristics often resemble the characteristics of Apraxia of Speech (AoS), a motor

speech disorder resulting from brain damage and different authors see FAS as a kind of

compensation strategy in relation to an underlying (mild) form of AoS (Mariën & Verhoeven,

2007, Whiteside & Varley, 1998; Moen, 2000; Miller, Lowit, & O’Sullivan, 2006; Fridriksson et al.,

2005; Kanjee, Watter, Sévigny, & Humphreys, 2010; Roy, Macoir, Martel-Sauvageau, &

Boudreault, 2012). According to Varley, Whiteside, Hammil, and Cooper (2006) FAS and AoS are

due to the same underlying deficit, but differ with respect to the possibility of a patient to

compensate or control their speech problems. Characteristics of FAS sometimes also resemble

characteristics of dysarthria. This holds, for example for the syllable isochronicity seen in FAS

speakers, but also in dysarthric speakers (Kent & Rosenbek, 1982). However, in dysarthric

speakers articulatory deficits are caused by an impairment of the articulatory musculature. These

deficits remain constant under all speech conditions, which is not seen in FAS.

Of course, listeners’ perception and familiarity with other languages plays an important

role in perceiving a foreign accent. Results from studies on perceiving a foreign accent in healthy

speakers (Flege, 1988, Di Dio, Schulz, & Gurd, 2006) show that listeners can detect foreignness in

milliseconds. However, a feature that is salient for one listener may not be for another

(Southwood & Flege, 1999) and furthermore these salient features are interpreted through the

listener’s experiential and attitudinal filters (Miller et al., 2006). Recently, Verhoeven, De Pauw,

Pettinato, Hirson, Van Borsel, and Mariën (2013) even showed that the foreign impression of the

listeners is different from the impression they get from real foreign accents. This means that we

assume that the foreign accent in FAS must not be seen as the deficit itself. Rather the speech of a

speaker with FAS is altered due to a brain deficit in such a way, that it no longer sounds like the

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original language of the speaker. We assume that the different aspects of the perception of FAS

can be combined to one underlying characteristic, namely increased force of articulation. 1

We will argue that listeners perceive a foreign accent in our FAS speaker because of a

larger amount of fortition (force of articulation) in his speech. Synchronically as well as

diachronically the term ‘fortition’ is used for segment changes, such as approximants changing

into fricatives; fricatives into plosives and voiced obstruents into voiceless obstruents. Changes in

the opposite direction are called ‘lenition’ (Lass, 1984). Fortition implies strengthening of the

overall force of the sound (Crystal, 2008).2 An increase in fortition will result in clear

segmentation, lack of assimilation and lack of vowel reduction and this is exactly what has been

reported for FAS. Laver (1994) also assumes that fortis sounds are characterized by a high general

speech tension.

Our attempt to explain FAS is comparable to former attempts of Miller et al. (2006)

Dankovicová and Hunt (2011) and Perkins and Ryalls (2013) who tried to explain the perceived

foreignness of FAS speakers on the basis of vowel, consonant cluster and stress pattern changes

playing an important role in making their accent sounding as foreign. Part of these characteristics

will be used in our model as well, but we will try to extend it to characteristics of fortition in

general.

We expect that the characteristics of fortis speech in FAS show that the direction in

perception of an accent will go from a language with relatively more lenition, like Dutch, into a

language with relatively less lenition, like German. Because this larger amount of force of

articulation manifests itself in different aspects of AA’s speech, we assume that we are able to 1 Force of articulation is not a general characteristic of speech disorders. In some types of dysarthria like in Parkinson’s disease, for example, also lenition processes occur. 2 The exact definition of ‘fortition’ in the phonological and phonetic literature is a matter of debate. In some cases the definitions of the opposition fortis-lenis even contradict. For example, the definition of the opposition is based on sonority by Kim and Chen (2007); they define fortition as suppression of lenition processes. Bauer (2008), on the other hand, describes lenition as the failure of realizing an underlying target segment. In this view, a segment such as /t/ can be both a fortis and a lenis variant. Consider the Dutch word hond ‘dog’, which is realized with a final [t]. This realized [t] of underlying target /d/ is an example of lenition according to Bauer, just like the flap in the American English realization of city, in which /t/ is the underlying target. This definition of the opposition fortis-lenis contradicts with the definition based on sonority in which fortition processes are only possible in one direction: in the Kim and Chen (2007) approach, /t/ is always more fortis than /d/ or flap. In this paper, we define the difference between lenis and fortis speech as a difference in force of articulation.

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account for the variation in perceived foreign accents. One could assume that perception of an

accent always moves towards a language spoken by a larger community. However, Moonis,

Svearer, Blumstein, Kurowski, Licho, Kramer, and Drachmon (1996), Coelho and Robb (2001),

Hall, Anderson, Filley, Newcombe, and Hughes (2003), Blumstein et al. (1987) all give examples of

FAS in which an American FAS speaker is perceived as speaking with a French accent, although

English is spoken by a larger number of people.

We will also try to show that it is not just the matter of one single aspect that could explain

the outcomes, like for example stress-timed languages perceived as syllable-timed languages. For

AA some speakers reported a French accent, which could be explained in this respect, but others

reported a German accent, where Dutch and German are both stress-timed languages. Therefore,

we will try to explain the perceived accents on the basis of a combination of phonological and

phonetic aspects of the speech of our FAS speaker. We will try to show this, by investigating the

effects of speech rate, stress patterns, vowel reduction, voice onset time, and assimilation in the

speech of AA. Before we describe the characteristics of AA, we first will provide an introduction

into some phonological aspects that are typical for the Dutch language.

Phonological aspects of Dutch

Stress pattern and vowel duration

Dutch, like German and English, has been described as a stress-timed language in which stressed

syllables occur at even intervals (Rietveld & Van Heuven, 2001). In these languages, stressed

syllables are allegedly longer than unstressed syllables. Vowel reduction takes place in unstressed

syllables. Abercrombie (1967), following Pike (1945), claims that in languages like French,

Spanish and Arabic all syllables have approximately the same duration. These languages are called

syllable-timed languages. Vowel reduction is less common in these languages.

Although Abercrombie’s controversial distinction of languages in stress-timed and

syllable-timed languages has been challenged, for instance by Roach (1982) and Liberman (2008),

it led to differences in prosodic organization of these languages. In Dutch, syllables are grouped

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into bounded trochaic feet in which the syllable in the weak non-initial position is often reduced

to schwa. In a syllable-timed language like French, on the other hand, syllables are grouped in

unbounded feet with final stress. All syllables have full vowels. This is for example illustrated in

example 1. In (1a) the Dutch version of the word “onomatopee” is given, in (1b) the French one .

(1) Feet parameter

a. Bounded feet (Dutch): (o no)∑ (ma to) ∑ (pee) ∑ [ʔon ma:t pe:]ə ə

b. Unbounded feet (French): (o no ma to pee) ∑ [ʔo:no:ma:to:pe:]

Voice onset time

Many language systems exhibit a contrast between so-called voiced plosives (/b,d, /) andɡ

voiceless plosives (/p,t,k/). The phonetic differences between these categories can be measured

as differences in Voice Onset Time (VOT), i.e. the time when vocal cord vibration starts following

the release burst of the plosive. However, the phonetic realization of this contrast in plosives is

not the same for all languages. Dutch realises initial prevocalic plosives such as /b/ and /d/ with

prevoicing: vocal cord vibration starts before the release burst of the plosive (Rietveld & Van

Heuven, 2001, Jansen, 2004). In other words, VOT has a negative value. Other language systems,

such as German, do not exhibit this prevoicing.3 The opposition /b/:/p/ in these languages is

accomplished by means of a longer VOT in the voiceless counterpart, which is perceived as

aspirated. Jansen (2004) distinguishes the two manners of categorization as an opposition

between negative and short lag positive VOT (Dutch), on the one hand, and as an opposition

between short lag and long lag VOT (German, English), on the other hand. He defines short lag as a

VOT between 0-36 msec. and long lag as a VOT larger than 36 msec. Thus, voiceless plosives in

Dutch, such as /p/ and /t/, are realised with a short lag positive VOT, whereas voiceless plosives

in German are realised with a long lag positive VOT. The longer the VOT, the more powerful the

3 An anonymous reviewer very properly observed that not all German dialects lack prevoicing, e.g. northern German dialects. These dialects exhibiting prevoicing, however, do not give the impression of a typical German accent to Dutch listeners.

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realization. Therefore, German exhibits more force of articulation in the realisation of these

plosives than Dutch.

Assimilation

As mentioned above, force of articulation causes more segmentation and, therefore, less

assimilation and co-articulation. Grijzenhout (2000) claims that the German word beweisbar

(”provable”) is preferably realised as [b isba r] with [sb], whereas the Dutch cognateəʋɑ ː

bewijsbaar is realised as [b izba r], with [zb]. Both German and Dutch colloquial speech exhibitəʋɛ ː

optionally regressive (and progressive) assimilation of voice in obstruent clusters, but only in

Dutch the assimilated forms are preferred. Both languages also exhibit regressive place

assimilation of nasals before obstruents. Again, the realization of a word like [ ŋko p n] forʔɪ ː ə

inkopen (”purchase”) is preferred to [ nko p n] in Dutch, whereas in German [ inkauf n] isʔɪ ː ə ʔɛ ə

preferred to [ iŋkauf n]. ʔɛ ə We see that German exhibits less assimilation than Dutch

(Grijzenhout, 2000) and, therefore, we conclude that German shows more force of articulation

than Dutch with respect to the concatenation of segments.

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Phonological aspects of Dutch and FAS speech

Only if we relate our phonetic analyses with the differences in phonological organization and

preferences between languages, can we account for the variation in perceived accents in Dutch

FAS speech. FAS speech is characterised by a lack of lenition processes, such as vowel reduction

and assimilation. For example, lack of assimilation can be observed in the way AA realises a

sentence such as ik ben alleen (”I am alone”) (obtained from an interview with AA). In this case,

we observe a lack of regressive assimilation of voice: the /k/ of ik is expected to be realised as [ ]ɡ

under influence of the right-hand neighbour /b/ in ben. In the upper graphs of Figure 1, a

spectrogram including the pitch contour as well as an oscillogram of a control speaker (see

Methods section) are shown. The vertical lines in the oscillogram indicate pulses. At these

positions the vocal cords vibrate. The first two words are realized as [ b n]. As can beʔɪɡ ɛ

observed, the entire fragment is voiced. In the lower part of Figure 1, the spectrogram and an

oscillogram of the realisation of the same two words by AA are depicted. Again the vertical lines in

the oscillogram indicate pulses, the voiced parts of the fragment. When the graphs are compared,

one can see the absence of assimilation in the fragment of AA, which may explain the perception of

a German accent.

Figure 1 about here

METHOD

Participants

AA is a right-handed, monolingual Dutch male. At the age of 59, he presented with a temporally

expressive aphasia and a right-sided hemi-hyperesthesia. The symptoms disappeared after an

hour. Medical examination revealed a stenosis of the internal coronary artery. Seventeen days

later the patient underwent surgery to remove the carotid stenosis, which was without

complications. However, when AA awoke from the anesthesia, he noticed reduced muscular

strength in his right leg and a complete paresis of the right arm. On the first day after surgery, the

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patient could not speak at all, later his speech improved. He was diagnosed with a stroke. When he

spoke again, the employees of the hospital wondered from which country he came, as they heard

him speaking with an unknown accent.

Neurological findings

Neurological examination showed a mild right-sided facial paresis, an almost complete paresis of

the right arm graded as MRC 2, and a mild paresis of the right leg, graded as MRC 4. During

neurological examination no signs of aphasia were present, only prosodic changes in his speech.

Magnetic resonance imaging (MRI) revealed an ischemic infarction in the left middle

cerebral artery territory and tissue loss in the right occipital lobe consistent with a small earlier

infarction. Areas involved were the left posterior supramarginal gyrus and the pre and post

central gyrus. MRI data are shown in figure 2. Several months after stroke a second MRI revealed

gliosis in the affected regions.

Figure 2 about here

Neurolinguistic findings

A neurolinguistic analysis revealed that AA’s speech rate was reduced and his speech was

sometimes halting. Speech and language assessment was done with subtests of the Aachen

Aphasia Test (AAT: Graetz, De Bleser, & Willmes, 1992), and several subtests of the Dutch PALPA

(Bastiaanse, Bosje, & Visch-Brink, 1995). The Boston Naming Test (Kaplan, Goodglass, &

Weintraub, 1983) was administered to assess word finding. Scores are given in Table 1.

Table 1 about here

The scores on all tests were within normal limits. AA had no word-finding problems, used no

semantic paraphasias and spoke grammatically correct. Repetition of non-words with one or two

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syllables was good, but repetition of non-words with more than two syllables resulted in haltering

speech and slips of the tongue, followed by self-correction. This haltering was less severe in

repetitions of words. In spontaneous speech, prosodic changes included unusual patterns of

timing and intonation. Reduced speech rate and less stress variation were noted for polysyllabic

words. The intonation of some of his sentences was inadequate. In conclusion, no evidence of

aphasia was found, but there were clear symptoms of FAS in AA’s speech. A diadochokinesis task,

mentioned in the test for dysarthria and Apraxia of Speech (DYVA; Dharmaperwira-Prins, 1998)

was administered and this task was difficult to perform for AA, especially with regard to

alternating diadochokinesis (/pataka/). Unfortunately, the DYVA is not a standardised or

validated test. Although a valid test for Apraxia of Speech (AoS) was not available when AA was

tested, clinical judgement gave the impression that AoS could not be ruled out. However,

assessment of the Radboud Dysartria Test (Knuijt, & Kalf 2007) did not reveal symptoms of

dysarthria.

Control data

All data of AA’s speech that were used for the analyses were compared with the data of a matched

control speaker: a 59-year old, monolingual Dutch speaker without a history of neurological

illness and without speech and language problems. He lived for his entire life in the same area as

AA and speaks with the same regional accent.

Materials and analysis

Qualitative analysis

33 first-year students of Linguistics and 19 second-year students of Speech Therapy with no or

basics knowledge in speech and language deficits were asked to listen to a fragment of one minute

of spontaneous speech of AA. This fragment did not contain reference to the diagnosis. The

students were asked whether they assumed that the speaker had an accent and if so, what accent

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they heard. They were told that it was possible to decide that there was no specific accent, a local

accent, a dialect or an accent from other languages. In case of an accent they had to write down

what accent they heard.

Quantitative analysis

AA’s speech was recorded during a series of speech production tasks involving reading aloud

words (multiple syllables, and CVC-structure), specifically designed to examine segmental

characteristics and a story taken from a test for dysarthria and AoS, the DYVA (Dharmaperwira-

Prins, 1998). The items of both testst are provided in the appendix. An Olympus digital voice

recorder, type VN5500PC was used. Five aspects of AA’s speech were analysed: speech rate, stress

pattern, vowel reduction, Voice Onset Time (VOT) and assimilation. PRAAT speech analysis

software (Boersma & Weenink, 2010) was used for the acoustic measures.

Speech rate

The speech rate was determined on the basis of an interview held with AA two weeks after stroke.

This recording was made during an interview with AA’s speech-therapist, and had a duration of 3

minutes and 13 seconds and contained a total number of 276 words. The number of syllables per

second was determined. For comparison, norm speech rate data for Dutch of Verhoeven, De Pauw,

and Kloots (2004) were used.

Stress pattern

The reading aloud test contained six polysyllabic words. These words were used to measure

syllable duration and vowel reduction. The words were: accepteren (”to accept”); logopedie

(“speech therapy”); tentoonstelling (”exhibition”); familie (”family”); fysiotherapie

(“physiotherapy”); and apparatuur (“hardware”). Duration values for each syllable were

measured from a waveform display. The length of stressed and unstressed syllables was

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measured in seconds and the mean length was determined. Furthermore, a ratio for stressed and

unstressed syllables was calculated.

Vowel reduction

For the six polysyllabic words that were analysed a phonetic transcription was made. As Dutch is

a stress-timed language, it was expected that vowels in unstressed position are more centralised.

This means that they resemble schwa more in unstressed position than in stressed position

(Gussenhoven, 2004).

Voice Onset Time

In line with Freeman, Sands, and Harris (1978), Kurowski, Blumstein, and Alexander (1996), and

Mauszycki, Dromey, and Wambaugh (2007), we measured VOTs for two pairs of consonants:

/p/vs./b/ and /t/ vs./d/. VOT’s were extracted for two pairs of consonants, each contrasting on

voicing. Twelve CVC words and non-words with initial stops /p,t,b,d/ followed by /a/, /o/,

and/e/, were used. The words are given in the appendix.

Assimilation

Words and word groups where assimilation was to be expected were selected and analysed with

respect to assimilation. The items were taken from the subtest reading aloud of the test for

dysarthria and AoS (DYVA; Dharmaperwira-Prins, 1998). The stimuli of interest for regressive

assimilation in nasals were: een person (“‘a person”), ingegaan (”entered”), ingeschakeld (“put

on”), and zijn geweest (“have been”). The nasals are supposed to have identical places of

articulation with their right-hand neighbours.

RESULTS

Qualitative analysis: Accent evaluations

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From the 52 students that were asked to evaluate the accent of AA, 15 students reported an

Arabic accent, 9 a Turkish accent, 9 heard a German or Eastern European accent, 6 an accent of

Surinam or the Dutch Antilles, 4 a French accent and 4 a Spanish accent. 3 students reported that

the speech of AA was standard Dutch and 2 mentioned a local dialect (Twents; a Dutch Low Saxon

dialect, spoken at the border with Germany), which was not the original dialect of AA.

Quantitative analyses

Speech rate

The speech rate determined from the interview two weeks after stroke shows a reduced number

of syllables per second as compared to the norm speech rate. The speech rate in AA is less than

half the number of syllables in comparison to this norm (see table 2).

Table 2 about here

A recording taken during a pre-stroke holiday trip was available for AA. Unfortunately, this

recording was of poor quality and could not be used for thorough phonological analyses.

Nevertheless, it was possible to determine the speech rate, which was 4,75 syllables per second,

resembling the norm speech rate.

Stress patterns: syllable duration

As mentioned above, Dutch is a stress-timed language in which the stressed syllables are normally

longer than the unstressed syllables. If too much force of articulation is used, the pronunciation of

each syllable is equally careful, resulting in less variation in syllable duration. This is exactly what

we observe in AA’s speech (see Figure 3).

Compared to the control speaker, the patterns of syllable duration of AA and the control

speaker within the words are different. In the word àpparatúur (“equipment”), for example, the

first and final syllables are in strong positions and should be stressed. The control speaker indeed

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realises stressed syllables longer than the unstressed ones. However, AA’s realization of the third

syllable in àpparatúur, which is in weak position, shows a longer duration than for example the

duration of the first and fourth syllable in strong positions.

Figure 3 about here

By measuring a ratio of stressed and unstressed syllables, it is possible to more objectively reveal

that there is a difference in length between stressed and unstressed syllables in the target words

of the control, but not of AA. Table 3 shows the mean length of stressed and unstressed syllables

and their ratio. The difference in length between stressed and unstressed syllables is almost

absent in the answers of AA.

Table 3 about here

Vowel reduction

In Table 4, the pronunciation of the 6 polysyllabic words in which vowel reduction could take

place is given. The six words spoken by AA show less vowel reduction than those spoken by the

control subject. In five out of the six words AA uses a full vowel where the control speaker uses a

schwa. For the cases where vowel reduction is observed for the control speaker and not for AA the

vowels are given in bold in Table 4. The control speaker pronounces these as schwas, whereas AA

realises these vowels as full vowels. Notice that vowel reduction is not completely absent in AA’s

speech: in the penultimate syllable of fysiotherapie (“physiotherapy”) AA does realise a schwa.

Table 4 about here

When we compare these vowel reductions with the syllable length mentioned in the previous

section, there is a relation. The syllables that AA realises with full vowels and the control speaker

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with schwas are of course also different in duration: AA’s full vowel syllables in unstressed

positions are longer than the comparable ones by the control speaker.

Voice Onset Time

One of the characteristics of the speech of AA is a lengthened VOT in voiceless plosives. Longer

VOTs indicate a more powerful realization. A word like thee (“tea”) is realised as [the:] instead of

standard Dutch [te:], leading to the perception of a German accent. In table 5 the mean VOT values

are given for the voiced and voiceless initial stops. The data show that AA’s voiced labials do not

have a negative value. The /b/ is pronounced with a positive value of VOT which makes it sound

like a /p/.

Table 5 about here

Assimilation

The results of the analysis with respect to the presence of assimilation are presented in Table 6.

Assimilation was observed in the realisations of the control speaker, but not in the data of AA. In

een person (“a person”), the control speaker realises the /n/, an alveolar nasal, as [m], a bilabial

nasal due to the influence of adjacent /p/, a bilabial plosive. In Table 6, all underlined places show

the process of assimilation.

Table 6 about here

DISCUSSION

Flege (1988) and Di Dio et al. (2006) demonstrated that listeners can detect foreignness in speech

by healthy speakers within milliseconds. In our study 52 students, who judged the accent of AA’s

FAS speech, mentioned various accents: Arabic, Turkish, French, Spanish and German. Evidently,

FAS is in the ear of the beholder. The participants only perceived accents they are familiar with in

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the Dutch community. If a listener is not familiar at all with e.g. an Arabic accent, he will not

perceive an Arabic accent in FAS speech. However, this only explains the variation in perception

partially.

We suggest that the increased force of articulation in AA’s speech plays a critical role in the

perception. Increased force of articulation causes less variation in syllable length and lack of

vowel reduction, on the one hand, and longer VOTs in case of plosives and lack of assimilation

processes, on the other hand. Comparison of the acoustic analyses of the speech of AA and the

control speaker reveals that all these characteristics of increased force of articulation are present

in AA’s production.

We showed that AA’s speech exhibits less variation in syllable duration, which is also

related to the lack of vowel reduction (also mentioned in Van Lancker et al., 1983; Whitaker,

1982; Blumstein et al., 1987; Ingram et al., 1992). Lack of vowel reduction as well as the ratio

between syllable duration in weak and strong prosodic position show that AA diminishes the

contrast between weak and strong syllables in his altered system after stroke in a way that

resembles a syllable-timed system more than the Dutch stress-timed system. This explains why

AA’s speech is perceived by some listeners as spoken with an accent of a language which is

syllable-timed, such as French, Spanish, Turkish or Arabic4.

The perception of a German accent can be explained as follows. The values of VOT in AA’s

plosives show that AA implements the contrast of voiced and voiceless plosives in an altered

system after stroke. The altered system, in which voiced plosives are realised with short lag VOT

4 The distinction between syllable-timed and stress-timed languages is rather controversial and this definitely holds for the status of Arabic. Auer (1991) characterizes Yoruba as exemplary for syllable-timed languages and English as exemplary for stress-timed languages. Arabic is positioned somewhere in between. It shares stress-timed language characteristics with English, such as being sensitive to assimilation processes, but syllable structure is less complex in Arabic and it allows for unreduced vowels in unstressed syllables. According to Auers grouping, Arabic is closer to French than to English. This is also confirmed specifically for Northern African Arabic (among which Moroccan Arabic, which is probably the Arabic Accent Dutch people are most familiar with), by Fagyal (2010) who showed that the rhythm of Arabic in bilingual Northern African Arabic speakers was comparable to that of the syllable-timed language French. The perception of an Arabic accent is therefore, like the perception of a French or Spanish accent in line with our hypothesis of increased force of articulation.

16

and voiceless plosives with long lag VOT, rather resembles the German than the Dutch system of

plosives (see also Ardila et al., 1988; Gurd et al., 1988; Ingram et al., 1992; Whitaker, 1982).

Furthermore, the increased force of articulation causes lack of assimilation and other lenition

processes in AA’s speech. Regressive and progressive assimilation of voice in obstruents and

regressive assimilation of place in nasals is very common in Dutch colloquial speech (Grijzenhout,

2000). In AA’s speech, the increased force of articulation results in a lack of assimilation. Both the

lengthened VOT in voiceless plosives and the lack of assimilation may enhance the impression of a

German accent.

Reconsidering the large amount of mentioned accents we could say that the perceptual

accent identification is linked to what kind of characteristic attracts the attention of the listener:

e.g. equal syllable duration may lead to the interpretation of a syllable-timed language such as

Spanish, whereas a segmental characteristic, such as the observed delayed vocal cord vibration,

may lead to the perception of a German accent.

Languages differ with respect to force of articulation which can explain why so many cases

of native English speakers with FAS have been described. This does not have to be a bias caused

by English being widely spoken or the amount of research done in English speaking countries. It

might rather be because English, especially American English, is a language with relatively little

force of articulation. When American English speakers suffer from FAS, it may sound like British

English, which has more force of articulation, and when a native British English speaker suffers

from FAS he may sound like a Scottish speaker. Nevertheless, most heard accents in American or

British English are German and French (Edwards, Patel, & Pople, 2005) which might be expected

with respect to aspects of force of articulation as explained above. A change to a German accent

seen in a Norwegian speaker, (Monrad-Krohn, 1947) and a British speaker (Whitty, 1964) can

both inter alia be due to lack of assimilation.5 Syllable isochronicity which can lead to a French

5 An anonymous reviewer assumes that the perceived German accent of this Norwegian speaker is caused by the inability of the patient to produce native pitch-accents, rather than caused by increased force of articulation. Indeed, Moen (1996) accounts for the speech of this patient in an autosegmental phonological way as a failure at the level of pitch-accent placement and as caused by inappropriate division of utterances into feet. However, her phonetic characterization of the speech is exemplary for increased force of articulation: variations in pitch were greater than usual in Norwegian (p. 162), with full vowels in contexts

17

impression is also seen in other British speakers (Gurd et al, 2001; Hall et al, 2003). In Mariën and

Verhoeven (2010), both German and French accents are heard in a Dutch speaker, which is

comparable to AA. For a Dutch speaker with FAS, the direction from relatively little force of

articulation to increased force of articulation is seen. Therefore, for a Dutch speaker with FAS an

accent with characteristics of the German or French language may be expected, whereas the

opposite, e.g. a French FAS speaker perceived as speaking with a Dutch accent is not. Of course,

the proof of this claim will lie in the impossibility to falsify it on the basis of former and new cases.

We are currently working on a review of a large number of FAS cases. In that study more fortition

parameters, such as expanded vowel space in hyperarticulated speech and higher formants after

plosives in high arousal speech, are added (see for an overview of the parameters: Gilbers,

Jonkers, Van der Scheer, & Feiken, 2013). Especially, counter-examples, e.g. a German FAS speaker

perceived as speaking with a Dutch accent, should be (re-)analysed, keeping in mind that

sometimes accent cues can be in conflict with each other. To give an example, the values of the

second formant (F2) play a role in the expansion of the vowel space, but they also play an

important role in measuring fortition in plosive-vowel combinations (Lindblom et al., 2007).

These two parameters are in conflict with respect to the F2 value of /u/. Expansion of the vowel

space would lead to a lower F2 value for /u/, but Lindblom et al. (2007) expect higher F2 values

for the /u/ after a fortis plosive. This conflict can be solved by assuming that there is a hierarchy

within the parameters for fortition mentioned in this paper. Like constraints in Optimality Theory

(Prince & Smolensky 1993), the fortition parameters might be ranked on the basis of dominance.

We hypothesise this ranking to be listener-specific.

CONCLUSION

AA is a monolingual speaker of Dutch who speaks with a foreign accent after stroke that was

perceived as French, Spanish, Arabic, Turkish and German. We argue that the changes in his

speech are caused by increased force of articulation, which results in less variation in syllable

where a reduced vowel was expected (p. 170) and a rise in pitch in utterance final positions (p. 170). These are characteristics of force of articulation we also found in the speech of AA.

18

length, lack of vowel reduction, delayed vocal cord vibration and lack of assimilation processes.

Only if we relate the attested increased force of articulation of our phonetic (acoustic) data to

differences in the phonological systems of the relevant languages, are we able to account for the

diversity in perceived accents, ranging from German to Arabic, in the same sample of FAS speech.

Acknowledgements

We would like to thank AA and the control speaker for their participation and Roelien Bastiaanse

for useful comments on an earlier version of this paper.

Declaration of interest: The authors report no conflicts of interest. The authors alone are

responsible for the content and writing of the paper.

19

APPENDIX

1. List of multisyllable and CVC words

Accepteren. Ik zal het moeten accepteren.

“to accept”. “I will have to accept it.”

Logopedie. Ik heb lang logopedie gevolgd.

“Speech therapy” “I have had speech therapy for a long time”.

Tentoonstelling. Die tentoonstelling was interessant.

“Exhibition”. “That exhibition was interesting.”

Familie. Mijn familie is groot

“Family”. “I do have a big family.”

Fysiotherapie. Een andere therapie is fysiotherapie.

“physiotherapy” “Another therapy is physiotherapy”

Apparatuur. Wat een mooie apparatuur.

“hardware” . “Nice hardware”

CVC-words

beet boot baat “bit – boat - benefit”

peet poot paat “nonword – leg – nonword”

teet toot taat “nonword – nonword – nonword”

deet doot daat “nonword – nonword – nonword”

20

2. Subtest reading aloud of the test for dysarthria and AoS (DYVA; Dharmaperwira-Prins 1998)

Loos alarm op het strand

Groot alarm, afgelopen donderdag op het strand van Zandvoort. De kustwacht was gewaarschuwd

dat er een persoon, die zich in het water had begeven, vermist was. Hij was tegelijk met nog twee

andere personen de zee ingegaan en nu waren die twee personen komen vertellen dat ze hem

misten. Ze waren er zeker van dat hij niet terug gegaan was naar het strand. De reddingsbrigades

van Zandvoort en IJmuiden werden daarom ingeschakeld om deze ene persoon te zoeken. Ook

werd er een helikopter ingezet. Een ziekenauto werd in gereedheid gebracht. Het alarm dat was

geslagen bleek loos te zijn, want er bleken niet drie maar twee personen in het water te zijn

geweest. Tot groot paniek leidde het alarm onder de badgasten echter niet. De meesten bleven

kalm en sloegen het een en ander met belangstelling gade.

“False alarm on the beach”

“Serious alarm, last Thursday on the beach of Zandvoort. The Coast Guard was alerted that a

person, who went into the water was missing. He had entered together with two other people the

sea and now those two people came to tell that they missed him. They were sure that he had not

gone back to the beach. The guards of Zandvoort and IJmuiden were therefore asked to look for

this person. There was also a helicopter. An ambulance came. The beaten alarm turned out to be

false because there were not three but two people in the water. The alarm did not lead to great

panic among the bathers. Most remained calm and watched with interest“.

21

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