Temporal control in the voicing contrast: Evidence from surgery-related apraxia of speech

ABSTRACT

The goal of this study was to investigate the phonetic realisation of the voicing feature in two tumour resection-related Spanish speakers with apraxia of speech. Temporal parameters related to the phonological contrast of voicing in Spanish have been analysed for intervocalic voiced and voiceless obstruents embedded in isolated words and nonwords, and compared with data collected from healthy speakers. Results indicate that in devoiced productions, where VOT values fitted the ‘voiceless stops’ category, vowel duration values matched those of voiced stops and suggested the preservation of contextual voicing cues. An attempt at preserving a consonant/vowel duration ratio consistent with aerodynamic predictions for voicing contrast has been observed in apraxic correct production as well as in devoicing errors, but not in the control group, which could be interpreted as a compensatory mechanism.

KEYWORDS:

• Apraxia of speech
• compensatory strategies
• speech errors
• voicing

Declaration of interest

The authors report no conflicts of interest.

Funding

Research supported by grants ANR-11-LABX-0036 (BLRI) and ANR-11-IDEX-0001-02 (A*MIDEX) and Spanish Ministry of Economy and Competitiveness, National Programme for Fostering Excellence in Scientific and Technical Research grant FFI2013-40419-P.

Notes

¹ Only for stops in stressed syllables.

² In intervocalic voiceless stops VOT was measured as the duration of signal between the burst release of the stop and the onset of the following vowel. In approximant allophones of the voiced plosives, we measured the ‘voicing bar’, i.e. a row of periodic energy in low frequencies, corresponding to the energy in the first and second harmonics from the consonant offset backward. Such measurements allow comparisons between intervocalic voiced consonants produced by control speakers and devoiced productions by apraxic speakers.

Additional information

Funding

Research supported by grants ANR-11-LABX-0036 (BLRI) and ANR-11-IDEX-0001-02 (A*MIDEX).