Flour or flower? Resolution of lexical ambiguity by emotional prosody in a non-native language

Abstract

It is well known that a speaker’s communicative intention and
his/her emotional state affect the prosodic characteristics of an
utterance. Emotional prosody can function as one type of
contextual cue that listeners adopt to disambiguate word
meaning or to derive word meaning from novel words in their
native language [1, 3, 4]. In this study we asked whether nonnative
speakers of English integrate emotional prosody during
resolution of lexical ambiguity. Based on a vocabulary test
with 32 native speakers of German, we selected a subset of the
original English homophone stimuli from [3]. In a two-alternative
forced-choice task, 71 native speakers of German
were required to choose the meaning of an English
homophone (with a happy, sad, and neutral meaning) spoken
in three different affective tones (happy, sad, and neutral) that
were congruent, incongruent, or neutral with respect to the
affective meaning. We found a significant emotion
congruency effect for sad but not for happy homophones.
Despite this asymmetry, the result suggests that non-native
listeners use emotional prosody during non-native lexical
selection.

Full text

Flour or flower? Resolution of lexical ambiguity by emotional prosody
in a non-native language
Adriana Hanulíková, Julia Haustein
University of Freiburg, Department of German studies, Germany
Adriana.Hanulikova@germanistik.uni-freiburg.de, Julia.Haustein@gmx.de
Abstract
It is well known that a speaker’s communicative intention and
his/her emotional state affect the prosodic characteristics of an
utterance. Emotional prosody can function as one type of
contextual cue that listeners adopt to disambiguate word
meaning or to derive word meaning from novel words in their
native language [1, 3, 4]. In this study we asked whether non-
native speakers of English integrate emotional prosody during
resolution of lexical ambiguity. Based on a vocabulary test
with 32 native speakers of German, we selected a subset of the
original English homophone stimuli from [3]. In a two-
alternative forced-choice task, 71 native speakers of German
were required to choose the meaning of an English
homophone (with a happy, sad, and neutral meaning) spoken
in three different affective tones (happy, sad, and neutral) that
were congruent, incongruent, or neutral with respect to the
affective meaning. We found a significant emotion
congruency effect for sad but not for happy homophones.
Despite this asymmetry, the result suggests that non-native
listeners use emotional prosody during non-native lexical
selection.
Index Terms: emotional prosody, tone of voice, lexical
ambiguity, non-native listeners, cross-linguistic recognition of
emotional prosody
1. Introduction
Prosody fulfills different functions during communication. At
the linguistic level, prosody can convey information about the
syntactic structure of an utterance, or signals various types of
utterances such as questions, exclamations, and statements. At
the paralinguistic level, prosody can convey a speaker’s
emotional state. Although emotional prosody is often linked to
affective and social aspects of communication, several studies
have shown that it conveys meaning [1, 2, 3], and thus may
facilitate various aspects of speech processing such as lexical
processing and naming [5, 10, 11], lexical and referential
disambiguation [3, 4, 9], or the assignment of meaning to
novel words [1, 6, 7, 8].
Previous studies have shown that speakers frequently
modulate their emotional prosody to convey additional
information about objects they are referring to, such as, among
others, size [1] and speed [9], and listeners use this
information to resolve referential ambiguity. For example,
novel adjectives such as “daxen” were typically produced
louder, slower, and with a lower pitch when they were
supposed to mean big as compared to small [1]. Speakers also
increased their speaking rate when they referred to fast moving
objects compared to slow moving objects [9]. In a two-
alternative forced-choice task (2AFC), listeners reliably
identified slow or fast-moving objects based on the speech rate.
Emotional prosody can also function as one type of several
contextual cues that listeners use to disambiguate words [3, 4].
Studies on lexical ambiguity resolution have often focused on
the time-course of sentential and semantic effects on the
selection of an appropriate meaning to disambiguate words
[3]. However, studies that include nonlinguistic aspects in
spoken-word processing suggest that emotional prosody is
equally relevant for the lexical-selection process [3, 4, 5, 11].
To evaluate effects of emotional prosody on the lexical
selection, [3, 4] used a transcription task and presented
listeners ambiguous homophones with an emotional (sad or
happy) meaning and a neutral meaning (e.g., banned/band).
The only context provided that would allow listeners to
resolve the lexical ambiguity was emotional prosody (e.g.,
banned/band spoken in a sad, happy, or a neutral tone of
voice). Upon hearing an ambiguous homophone, listeners
were more likely to transcribe the appropriate meaning when it
was spoken in a congruent affective tone (e.g., banned in a sad
tone of voice), suggesting that they integrated emotional
prosody during lexical processing and constrained the
selection of word meaning. In addition, [4] found that sad
participants were more likely to transcribe sad meanings than
were happy participants, suggesting that a subject’s emotional
state modulates processing of ambiguous lexical
representations.
Emotional prosody can effectively serve as a contextual
cue to help resolve lexical ambiguities. We asked here whether
non-native (L2) listeners, too, are sensitive to emotional
prosody as a cue to the intended meaning in homophones. So
far, little is known about how communicative aspects of
prosody are integrated during L2 speech processing. The
classroom-based acquisition of foreign languages usually
focuses on vocabulary, grammar, and pronunciation.
Communicative aspects of prosody are not usually covered,
possibly because it is often assumed that cross-linguistic
variation in the suprasegmental modulation (such as pitch,
speech rate and amplitude) that conveys emotions such as
sadness and happiness may be relatively limited, although this
issue is still under debate [12, 13, 14, 15]. It has been
suggested that both native and non-native speakers show
relatively high categorization scores of emotional prosody
such as happiness and sadness, and that the processing of
emotional prosody (e.g., sadness and happiness) does not seem
to depend on L2 proficiency [15]. According to this view, one
would assume that affective prosodic markers are universal
and it would be less surprising that non-native speakers can
use these cues given that native speakers have been able to do
so. However, while L2 listeners may be able to recognize and
categorize emotional prosody well, it remains an open

question whether they are able to integrate this information
during L2 lexical processing.
In this study, we employed a similar design and the
original stimuli and recordings from [3], but changed two
important aspects; we used only a subset of the original stimuli
and selected words that German learners of English were
likely to know. This was necessary, because listeners would
not be able to disambiguate between the two meanings of a
homophone if the words were unknown. Furthermore, instead
of a transcription task, we opted for a two-alternative forced-
choice task, a task that is frequently applied in the research of
emotions [15]. The main reasons for choosing a 2AFC task
instead of a transcription task were that a) L2 listeners’
possible insecurities in homophone spelling could lead to
biased responses, and b) the relative frequencies for both
meanings of a homophone may differ substantially between
L1 and L2 listeners, increasing biased responses for familiar or
frequent words in an L2. We reasoned that a visual
presentation of both meanings of a lexically ambiguous
homophone following an auditory presentation would allow us
to directly assess the effect of emotional prosody on ambiguity
resolution and to minimize word frequency and familiarity
effects in an L2. Although [3] have matched both meanings of
a homophone for the relative L1 frequency use, it is difficult to
assess whether the frequencies would be comparable from the
perspective of an L2 listener.
We anticipated that participants’ affective states could
influence lexical responses. Previous research has shown that
comprehenders’ affective states can substantially modulate
aspects of language processing; for example, semantic
processing during discourse comprehension [16, 17],
referential processing [18, 19], or mood incongruent word
processing [4, 20, 21]. Since we wanted to keep the design as
comparable as possible to [3], we did not use a mood
induction procedure; instead, we asked L2 participants to rate
their mood before starting the experiment.
2. Experiment
The main 2AFC experiment consisted of two parts: 1)
listening to homophones one at a time and assigning each
homophone to one of two possible meanings presented
visually on a screen, and 2) a vocabulary questionnaire to
determine L2 listeners’ familiarity with the critical
homophones. Before conducting the main experiment, a
vocabulary translation test with an additional group of
participants was run to determine L2 speakers’ familiarity with
both meanings of a homophone, and to select homophones for
which each of the two meanings were correctly translated
more than 50% of the time.
We predicted that if L2 speakers are able to integrate
emotional prosody during lexical processing, we should obtain
similar results as those for native listeners: more happy-
meaning responses for the happy/neutral homophones when
the words were produced in a happy tone of voice; and
similarly, more sad-meaning responses for the sad/neutral
homophones when the words were produced in a sad tone of
voice. Based on previous research on recognition of emotions
[see 15, for a review] and the results in [3, 4], we also
expected the results to be slightly more pronounced for the
sad/neutral homophones.
2.1. Methods
2.1.1. Participants
Participants were 103 students from the University of
Freiburg, all native speakers of German. Thirty-two students
(mean age 22.8, range 21-29, 7 men, average years learning
English 13.2, range 9-20 years) participated in the vocabulary
translation test. These students were enrolled in German
language and literature studies at the department of German
studies. Seventy-one students (mean age 23.8, range 20-31, 16
men, average years learning English 9.7, range 4-14 years)
participated in the 2AFC experiment. All 71 participants
studied English and were enrolled at the department of English
studies. All participants volunteered to participate. None of the
students reported hearing difficulties.
2.1.2. Materials
For the vocabulary translation test, both meanings of all 35
homophones (e.g., flower/flour) used in the original study [3]
along with 17 filler (non-homophone) words were presented
visually (with spellings) to native speakers of German in a
randomized order. The two possible meanings of each
homophone were never presented in pairs.
Based on the results of the vocabulary test, we selected 24
homophone pairs for the 2AFC experiment. We used the
original recordings from [3], and only the female amateur
actor from these. This speaker was a native speaker of
American English (and the recordings were done in the USA
for the purposes described in [3]). In the original study, all
homophones were matched for frequency, and the affective
meaning of each homophone pair was determined in a separate
rating experiment. A detailed description of the affective
homophone meaning ratings, the homophone selection, and
the stimuli recordings can be found in [3].
We created three experimental lists so that each
homophone occurred in only one of the three affective tones
(happy, sad, neutral) per list. The order of stimuli was
randomized so that tone of voice and homophone type were
spread across the list. Each list contained 12 homophones with
happy/neutral affective meanings (flower/flour, ate/eight,
knows/nose, rose/raws, won/one, tide/tied, medal/metal,
dear/deer, peace/piece, presents/presence, heal/heel,
sweet/suite) and six with sad/neutral meanings (bored/board,
missed/mist, blue/blew, banned/band, thrown/throne,
lone/loan). We also included six filler homophones with
neutral/neutral meanings (e.g., pause/paws, choose/chews,
cord/chord, heard/herd).
2.1.3. Procedure
All participants were tested in small groups in a quiet seminar-
room setting. Participants in the vocabulary translation test
were asked to provide a German translation for each English
word presented visually on a list. They were told to guess the
meaning of a word in cases where they were uncertain.
For the 2AFC experiment, participants were seated in front
of a large screen in a seminar room. Before starting the
experiment, they had to indicate their mood on a seven-point
Likert-type scale (with 1 indicating a very good mood). They
were told that they would hear (over loudspeakers) words that
can have two meanings, and that they would see the two
possible meanings on the screen. They were required to
indicate on an answer sheet which of the two meanings the

speaker intended to say. Participants had four seconds to make
a decision. The experiment started with a practice trial
including two example homophone items. After the
experiment, they were invited to fill in a language-history
questionnaire and to provide feedback on the experiment. To
evaluate participants’ strategic responses, we asked them
whether they were aware of the presence of homophones and
their emotional meanings.
2.2. Results
2.2.1. Vocabulary translation study
All translation responses were coded manually; each response
was categorized either as an incorrect translation, no response,
a correct translation, a related meaning, or a translation of the
other homophone (e.g., Blume ‘flower’ when presented with
flour). We excluded all homophone pairs that obtained more
than 50% incorrect responses (no response and a translation of
the other homophone counted as incorrect). Pairs for which
one of the two meanings was incorrectly translated more than
50% of the time were also excluded (e.g., tow/toe, hall/haul,
bridle/bridal, petal/pedal, die/dye, groan/grown, pain/pane,
poor/pore/pour, hair/hare). We also excluded cognates or
similarly sounding words in German (e.g., caller/collar,
medal/metal). Based on these exclusion criteria, a set of 12
happy/neutral and six sad/neutral homophones remained for
the 2AFC experiment.
2.2.2. Lexical disambiguation study
As can be seen in Table 1 (overall proportions) and Figure 1
(estimated effects), non-native speakers of English were more
likely to choose the sad meaning of a sad/neutral homophone
pair when it was presented in a sad tone of voice. This
replicates the effect observed for native English speakers in
[3]. However, unlike in [3], a less clear effect of tone of voice
on lexical disambiguation is visible for the happy
homophones.
Figure 1: Estimates of emotional homophone choices
(emo.selected) as a function of Tone of Voice and Homophone
Type (type of pair). The error bars represent 95% confidence
intervals.
To control for subject and item level variability in the data
analysis, a generalized mixed-effects logistic regression model
(implemented in R package lme4, [22]) for binary responses
was fitted. The proportion of selected emotional meaning per
homophone pair was taken as the dependent variable.
Treatment coding was used on the independent variables Tone
of Voice (happy, neutral, and sad) and Homophone Type
(happy/neutral and sad/neutral). The model includes random
intercepts for listeners and items, and random slopes for Tone
of Voice (by items). A model including random slopes for
mood (by items) as well as the interaction of Tone of Voice
and Homophone Type (by subjects) did not converge. The
summary results of the final model are shown in Table 2. The
results show that the interaction between Tone of Voice and
Homophone Type is driven by the responses to the sad/neutral
homophones in the sad tone of voice. We then applied Anova
(type III Wald chisquare tests) to the model and found a
significant main effect of Tone of Voice (X2 (2) = 6.81, p =
0.03) and a significant interaction between Tone of Voice and
Homophone Type (X2 (2) = 6.11, p < 0.05).
Table 1. Percentage of emotional homophone choices
for all participants and separately for participants in a
happy, sad, and neutral mood (ToV = Tone of Voice).
Happy/Neutral
Homophones
Sad/Neutral
Homophones
ToV:
happy
neutral
sad
happy
neutral
sad
Good mood
55.2
43.9
52.5
42.7
49.4
68.3
Sad mood
58.3
56.3
66.0
41.7
37.5
56.5
Neutral
mood
45.8
52.8
48.6
44.4
58.3
65.7
All (n = 71)
53.0
48.2
54.1
44.4
49.6
65.7
Table 2. Mixed-effects model result summary with
coefficient estimates β, standard errors SE, z-scores
and p values (ToV = Tone of Voice, HType =
Homophone Type, neut = neutral).
Predictor
β
SE
z
p
Intercept
0.162
0.288
0.56
0.57
ToV neut
-0.243
0.261
-0.93
0.35
ToV sad
0.005
0.265
0.02
0.99
HType sad/neut
-0.509
0.484
-1.05
0.29
Mood neut
-0.008
0.161
-0.05
0.96
Mood sad
0.174
0.189
0.92
0.36
ToV neut*HType sad/neut
0.608
0.447
1.36
0.17
ToV sad*HType sad/neut
1.139
0.464
2.46
0.01
Note: Formula: emo.selected ~ ToneOfVoice * type.of.pair + mood +
(1 |VP) + (ToneOfVoice |Item)
Separate models restricted to pairwise comparisons for the
sad/neutral and happy/neutral homophone pairs showed that
the percentage of sad homophones chosen was significantly
larger in the sad tone of voice relative to the happy tone of
voice (β!=!-1.176, z!=!-2.51, p!=!0.012) or to the neutral tone of
voice (β!=!-0.898, z!=!-2.41, p!=!0.016), but there was no
significant difference between the happy tone of voice and the
neutral tone of voice. The choices within the happy/neutral
homophone pairs did not significantly differ from each other.
This result indicates that non-native listeners detect the
relevance of emotional prosody for lexical disambiguation, but
they do so reliably only in the sad tone of voice. Similar
ToneOfVoice*type.of.pair effect plot
ToneOfVoice
emo.selected
0.3
0.4
0.5
0.6
0.7
0.8
happy neutral sad
●
●
●
type.of.pair
happy/neutral
sad/neutral
●

asymmetric patterns have been previously reported [e.g., 3, 4],
and we will come back to this asymmetry in the discussion.
To assess whether participants’ mood modulated the
integration of affective prosody during lexical meaning
disambiguation, we asked participants to indicate their mood
on a seven-point Likert-type scale ahead of the experiment.
Based on this information, three groups emerged (see Table 1
for percentage of homophone disambiguations for each mood
group): 40 participants in a happy mood (1-3 on the scale), 18
participants in a neutral mood (4 on the scale), and 12
participants in a sad mood (5-7 on the scale). However, since
no main effect of mood emerged and the analysis is based on
subjective ratings provided by the participants, further
research would be necessary to evaluate the nature of mood
effects on L2 lexical disambiguation.
We further analyzed the vocabulary questionnaire and
listeners’ feedback on the experiment. In the vocabulary
questionnaire, 27 participants indicated that they did not know
some of the homophones. Across all items for this group of
participants, 51 words were marked as unknown, the majority
of which (n = 36) were fillers (neutral/neutral homophones).
The remaining 15 critical unknown items consisted of the
following words: lone (n = 4), loan and mist (each three
times), rows (two times), and thrown, heel, won (each once).
This suggests that L2 participants’ knowledge of the
homophone lexical meanings was very high and cannot
explain the lack of a congruency effect for happy/neutral
homophones.
In the feedback requested from participants, only six
participants indicated that they did not realize that
homophones had been used, and 15 reported that they did not
realize that the homophones had emotional meanings. In
describing how they made their choices, they chose between
deciding intuitively (n = 29), based on the prosody (n = 6),
based on the word frequency (n = 5), and based on a match
between the pronunciation and the meaning (n = 15); the
remaining participants did not provide an answer. When asked
to guess the aim of the experiment, participants indicated that
the study examined effects of intonation (n = 16), emotions (n
= 16), and mood (n = 8) on word selection. Other responses
included the study of gender, frequency, word recognition,
comprehension, minimal pairs, associations, learning
processes, and language competence. None of the participants
reported being aware of the presence of one emotional and one
neutral meaning of a given homophone, or the link between a
homophone meaning and emotional prosody. We therefore
assume that participants did not develop a specific strategy
that would explicitly match the experiment’s demands.
3. Discussion
In a 2AFC experiment, we used homophones with either a
happy/neutral emotional meaning (e.g., flower/flour) or a
sad/neutral emotional meaning (e.g., banned/band) to examine
whether German listeners make use of emotional tone of voice
to resolve lexical ambiguity in English single words. For
sad/neutral homophones, results were, as predicted, that a sad
tone of voice led to more sad homophone choices than a happy
or neutral tone of voice. For happy/neutral homophones,
however, no clear effect of tone of voice on lexical
disambiguation emerged.
There are several possible explanations for why we
observed an asymmetry in the modulation of lexical
disambiguation by a sad and a happy tone of voice. First,
studies conducted on various languages suggest that sad
emotional prosody is frequently more accurately recognized
than happy emotional prosody [see 15, for a review]; and our
result extends this tendency to lexical processing. A similar
asymmetric pattern of results emerged for native speakers of
English in [3], with disambiguation effects being clearer for
sad/neutral homophones.
Second, it is possible that L2 participants did not activate
the same emotional meaning for some of the English
homophones which would have made them comparable to the
emotional meaning ratings provided by L1 speakers. It has
been previously suggested that emotional meaning
associations may even vary among native speakers [4]; it is
therefore reasonable to assume that cross-cultural differences
would play a role. For example, the word hymn, associated
with happy emotions by native speakers in [3], may be
associated with a neutral meaning and would then not differ
from the neutral homophone him. Future cross-linguistic
studies should collect associations with English homophones
to make sure that the appropriate emotional meanings are
activated.
Last but not least, it is possible that participants’ moods
contribute to asymmetric patterns in the use of emotional
prosody. However, we only collected subjective mood ratings
and did not expose participants to a happy or a sad mood
induction; different results might be obtained with a
systematic mood manipulation [see 4].
Taken together, these findings indicate that non-native
speakers are able to make use of emotional prosody to
disambiguate homophones in their L2, in particular for
sad/neutral homophones. Put differently, L2 listeners can access
meanings of ambiguous words that are congruent with affective
properties of the speakers’ utterances. However, unlike L1
listeners, they may be slightly less effective in constraining their
selection of word meaning. While L2 listeners detect the
meaning associated with the emotional prosody, the activation
spread to emotion-related lexical representations may require
increased computational effort (it usually takes longer to access
an L2 than an L1 lexical representation) as well as increased
exposure to prosodic information of a given speaker and a given
non-native language. Further research is needed that establishes
a) cross-linguistic affective ratings for each pair of homophones,
and b) effects of mood on L2 word processing by manipulating
participants’ emotional states. Furthermore, future studies could
address how presentation of single words with different prosody
will scale up in a sentential context, and consider the use of
online tasks.
4. Conclusions
We showed that non-native listeners are able to use emotional
prosody for lexical disambiguation, but they do so mainly for
sad/neutral homophones. The present result partly replicates
previous research on the role of emotional prosody in the
resolution of lexical ambiguity [3, 4] and extends this research
to a non-native population. This result forms the basis for
further research into the role of emotional prosody on lexical
processing and ambiguity resolution in L2 listeners. A
successful integration of contextual cues such as emotional
prosody could be a beneficial tool for vocabulary learning, as it
would facilitate the mapping process between labels and
referents.

5. Acknowledgements
We would like to thank Lynne Nygaard for providing her
original stimuli and recordings, Lars Konieczny for statistical
advice, and the reviewers for very helpful and constructive
feedback.
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