Dicky Gilbers

Normal-Hearing Listeners’ and Cochlear Implant Users’ Perception of Pitch Cues in Emotional Speech

In cochlear implants (CIs), acoustic speech cues, especially for pitch, are delivered in a degraded form. This study’s aim is to assess whether due to degraded pitch cues, normal-hearing listeners and CI users employ different perceptual strategies to recognize vocal emotions, and, if so, how these differ. Voice actors were recorded pronouncing a nonce word in four different emotions: anger, sadness, joy, and relief. These recordings’ pitch cues were phonetically analyzed. The recordings were used to test 20 normal-hearing listeners’ and 20 CI users’ emotion recognition. In congruence with previous studies, high-arousal emotions had a higher mean pitch, wider pitch range, and more dominant pitches than low-arousal emotions. Regarding pitch, speakers did not differentiate emotions based on valence but on arousal. Normal-hearing listeners outperformed CI users in emotion recognition, even when presented with CI simulated stimuli. However, only normal-hearing listeners recognized one particular actor’s emotions worse than the other actors’. The groups behaved differently when presented with similar input, showing that they had to employ differing strategies. Considering the respective speaker’s deviating pronunciation, it appears that for normal-hearing listeners, mean pitch is a more salient cue than pitch range, whereas CI users are biased toward pitch range cues.

Sonority substitutions in Broca's and conduction aphasia

Conduction aphasia is characterized by the production of phonemic paraphasias. These errors are assumed to be attributed to a breakdown in phonological processing, that is, in transforming the underspecified lexical-phonological form into a phonemic representation. Some Brocas aphasics also produce a considerable number of phonemic errors, due to a disorder in phonetic processing, namely, planning and executing the articulatory programs. Despite the fact that the phonemic errors in these two aphasia types arise at different levels, they are hard to distinguish. Some phonologists suggested that a distinction should be made between articulatorily based and phonologically based features. Although most features can be accounted for in articulatory terms (e.g. voice, labial), some are primarily motivated for phonological tasks. One of those features is [sonorant]. It is therefore hypothesized that substitutional errors concerning sonority will occur in conduction aphasia, but not in Brocas aphasia. This hypothesis has been tested and the results show that conduction aphasics indeed produce significantly more sonority substitutions than Brocas aphasics, but that the latter group does produce a few sonority substitutions as well. Several explanations for these phenomena are discussed.

Foreign accent syndrome and force of articulation

Background: Foreign accent syndrome (FAS) is a rare, acquired neurogenic disorder characterised by altered speech that sounds foreign, for example, English with a French accent. Several prosodic and acoustic changes have been mentioned in the literature, but none has indicated an underlying mechanism clarifying the accent in speech. Aims: The present case study aims to capture the acoustic changes in the speech of a Dutch FAS speaker under one heading: increased force of articulation. Methods & Procedures: Some of the often described characteristics of FAS concerning speech rate, stress patterns, vowel reduction, voice onset time (VOT) and assimilation were analysed in the speech of a Dutch male (AA) who speaks with a foreign accent after a stroke. Fifty-two students of Linguistics and Speech Therapy were asked to evaluate the accent of AA and came up with a variety of perceived accents, like Arabic, Turkish, German, Spanish and French. Outcomes & Results: We argue that all investigated characteristics reveal an increase in force of articulation. The reported variation in perceived accents can be explained by a different focus on the variety of phonetic aspects of FAS related to the differences between the phonological systems of the perceived languages and Dutch. Conclusions: Increased force of articulation may lead to the perception of different foreign accents in speakers with FAS. The specific accent depends on the focus of the listener on one of the phonetic aspects of force of articulation.

SONORANT SUSTAINMENT - A SINGLE-CASE STUDY OF A RARE PHONEMIC DEFICIT IN APHASIA

This single case study treats a rare, if not unique, symptom: sonorant sustainment. The patient involved suffers from a mild anomia, but apart from that he sustains sonorants in very strictly defined positions in the utterance. Detailed analysis of his spontaneous speech reveals that sustainment of sonorants is determined by certain phonological domains, whereas other phonological domains are of no influence at all. We have tried to establish the exact locus of impairment, which is assumed to be postlexical and prephonetic. Hence, sonorant sustainment may be considered a phonemic paraphasia. A possible explanation for sustainment of the sonorants is proposed within the framework of phonological domains.

Conflicting constraints: An introduction to optimality theory

In this introductory article we sketch out some of the general principles and merits of Optimality Theory, and provide a background to the articles contained in this special Lingua issue that centers around the concept and consequences of conflicting constraints within this framework.

Phonological length, phonetic duration and aphasia

This study discusses an error type that is expected to occur in aphasics suffering from a phonological disorder, i.e. Wernickes and conduction aphasics, but not in aphasics suffering from a phonetic disorder, i.e. Brocas aphasics. The critical notion is ‘phonological length’. It will be argued that it is impossible to define phonological length in articulatory-phonetic terms. Rather it should be defined in structural, that is, purely phonological terms. This suggests that the difference between the pairs /a,i,e,o,u/, the so-called long vowels, and /a,i,s,o,u/, the so-called short vowels, is phonologically based and not phonetically based. It is thus hypothesized that errors concerning phonological length may occur in patients with a phonological disorder, but are not expected in patients with an articulatory problem. To test this hypothesis an error analysis was made of the phonemic paraphasias produced by seven Brocas, four conduction and two Wernickes aphasics. The results support the hypothesis: co...

The common denominator in the perception of accents in cases with foreign accent syndrome

ABSTRACT Background: Foreign accent syndrome (FAS) is a rare speech disorder leading to a perceived presence of a new accent in a speaker’s speech. Until now, around 100 cases of FAS have been reported. It is striking that in most cases the perception of the accent is in one consistent direction, namely from languages like English or Dutch to accents of Romance, Germanic, Eastern European or tonal languages. Aims: In this article, we will try to come up with an overarching explanation for the accent changes seen in FAS, relating these changes to force of articulation. Main Contribution: We assume that the foreign accent in FAS is interpreted on the basis of the stereotypical segmental and prosodic characteristics that relate to the phonetics and phonology of specific languages. We hypothesise that the direction in perception of a FAS accent will go from a language characterised by relatively more lenition processes, into languages with relatively more fortition characteristics in their phonetic realisations and phonological system and not the other way around. Accents are expected to change from stress-timed to syllable-timed languages, from weight-sensitive stress systems to weight-insensitive systems, from non-aspirated to aspirated systems, and within these language groups from languages characterised by, for example, relatively more reduction and assimilation processes to languages with relatively less lenition. We have tested our hypothesis with the already described FAS cases. We restricted ourselves to the cases of neurogenic FAS described in English and to which enough details were provided in order to be able to judge the change of accent. Conclusions: From the 58 cases that fitted with these criteria, almost 90% showed a change of accent in the expected direction or did not contradict our hypothesis. Only six accent changes did not directly support it. The reported phonetic descriptions of the cases, if available, nevertheless suggest that they do not seem to completely violate our hypothesis.