Effects of low-pass filtering on English speech-in-noise recognition in auditory-only and audiovisual modalities for late bilinguals and monolinguals

The purpose of this study was to examine the impact of acoustic filtering and modality on speech-in-noise recognition for Spanish-English late bilinguals (who were exposed to English after their 5th birthday) and English monolinguals. All speech perception testing was conducted in English. Speech reception thresholds (SRTs) were estimated at 50% recognition accuracy in an open-set sentence recognition task in the presence of speech-shaped noise (SSN) in both low-pass and no-filter conditions. Consonant recognition was assessed in a closed-set identification task in SSN in four conditions: low-pass and no-filter stimuli presented in auditory-only (AO) and audiovisual (AV) modalities. Results indicated that monolinguals outperformed late bilinguals in all conditions. Late bilinguals and monolinguals were similarly impacted by acoustic filtering. Some data indicated that monolinguals may be more adept at integrating auditory and visual cues than late bilinguals. Theoretical and practical implications are discussed.