Role of language familiarity in understanding speech in noise under various acoustic environments

We communicate in complex acoustic environments in everyday life but our familiarity with the language can affect how well we can understand speech in these environments. The current study examines the role of language familiarity in understanding speech in varying acoustic environments via a speech intelligibility test conducted under anechoic and reverberant conditions with various speech-noise separation angles. Four groups were recruited with differing level of language familiarity: first language (L1) New Zealand English (NZE) listeners, second language (L2) Japanese native listeners with exposure to NZE, L2 Japanese native listeners with overseas English experiences without exposure to NZE, and Japanese native listeners who have learnt English as a foreign language (FL) without overseas English experiences. The L1 group performed better in overall speech intelligibility performance compared to the 3 Japanese native groups. Contrary to previous literature where non-native listeners were found to have a similar benefit from spatial separation to native listeners, this was not the case for the FL group, suggesting that this benefit is only available for listeners with a certain level of language familiarity. While there were differences between L2 and FL groups in the anechoic condition, these differences become marginal in the reverberant conditions for the two groups with little exposure to NZE. This suggests that familiarity to the specific language variety has an advantage in acoustically adverse environments. • Speech recognition tested for 4 participant groups differing in familiarity to NZE. • Conditions varied in room acoustics and spatial separation between source and noise. • Benefit from spatial cues only available for listeners with a certain level of language familiarity. • Advantages when familiar with specific language variety.