Speech is almost never delivered in ideal quiet conditions. On the contrary, the acoustic signal reaching a listener's ears is degraded by background noise and reverberations. The current study investigates the perception of the voicing contrast of initial stops in English by Polish non-native listeners. Previous research showed that Polish learners do not match native speakers of English in production and perception of English voiced and voiceless stops, which results from different phonetic implementations of voicing in the two languages. In the current study, two groups of Polish listeners recognised voicing of English initial stops in one-syllable words both in quiet and in six-talker babble. The results revealed different patterns of recognition for the two conditions. The place of articulation interacted significantly with voicing both in quiet and in noise, however results obtained suggest that performance in noise did not simply reflect the performance in quiet.

In the current study, we test the discrimination of four basic English tone contours in monosyllabic words by Polish learners using an AXB task and we compare these results to the results of an identification test. Discrimination does not require access to phonological labels and is claimed to tap core auditory mechanism. Relatively high discrimination performance by Polish learners and poor identification performance indicate that difficulties with correct identification of English tones are solely difficulties with labelling.