Learning to Understand Speech in Babble Noise: The Role of Rhythm Perception in English and Spanish

Perceptual learning—the ability to improve understanding of degraded speech with exposure—has been shown to occur across languages when speech is masked by stationary noise. However, it is unknown whether this holds for more complex maskers like babble noise, which introduces both energetic and informational masking. Compared to stationary noise, babble has greater rhythmic complexity, which may interfere with listeners’ ability to use rhythmic cues for perceptual learning, particularly for stress-timed languages like English. In a previous study, rhythm perception predicted perceptual learning for English-speaking but not Spanish-speaking listeners, suggesting that the role of rhythm in perceptual learning may be language specific; whether this relationship remains in the presence of rhythmically complex babble remains an open question. Native English-speaking and Spanish-speaking listeners (N = 77) completed a perceptual learning paradigm (pretest, training, posttest) with low predictability phrases masked by four-talker babble noise, followed by a rhythm perception task. Listeners in both groups showed significant perceptual learning, but Spanish-speaking listeners demonstrated greater intelligibility improvement. Rhythm perception did not predict learning in either group, suggesting that babble noise disrupts rhythm-based perceptual learning strategies. These findings highlight that perceptual learning in babble is influenced by language-specific rhythmic properties and that rhythm perception may play a reduced role in more complex masking conditions.