Voicing influences the saliency of place of articulation in audio-visual speech perception in babble

Previous research has shown that voicing can influence the perception of consonant place of articulation (POA) in audiovisual (AV) speech perception, although findings are inconsistent and often differ with the use of background noise. The prediction in the current study was that the AV perception of voiced and voiceless stop consonant POA is influenced by the differences in spectral distribution between voiced and voiceless stops, a hypothesis not compatible with the direction of the voicing effect shifting with different types of noise. Fifteen young adults were tested using incongruent AV stimuli that differed in POA, in a voiced and a voiceless condition, applying the infrequently used babble noise as background. As predicted participants used the auditory modality to a greater extent identifying the POA of voiced stops compared to voiceless stops. The more distinct spectral distribution of the voiced stops may contribute to them being more easily identified auditorily on the POA dimension than the voiceless stops. The study extends previous research using white noise, by demonstrating a consistent pattern of results in babble noise.