Speech perception runs smoothly and automatically when there is silence in the background, but when the speech signal is degraded by background noise or by reverberation, effortful cognitive processing is needed to compensate for the signal distortion. Previous research has typically investigated the effects of signal-to-noise ratio (SNR) and reverberation time in isolation, whilst few have looked at their interaction. In this study, we probed how reverberation time and SNR influence recall of words presented in participants’ first- (L1) and second-language (L2). A total of 72 children (10 years old) participated in this study. The to-be-recalled wordlists were played back with two different reverberation times (0.3 and 1.2 sec) crossed with two different SNRs (+3 dBA and +12 dBA). Children recalled fewer words when the spoken words were presented in L2 in comparison with recall of spoken words presented in L1. Words that were presented with a high SNR (+12 dBA) improved recall compared to a low SNR (+3 dBA). Reverberation time interacted with SNR to the effect that at +12 dB the shorter reverberation time improved recall, but at +3 dB it impaired recall. The effects of the physical sound variables (SNR and reverberation time) did not interact with language.

Noise impairs speech perception which in turn makes memory and learning more difficult. School children are expected to be particularly vulnerable to the negative effects of noise. In this study we varied reverberation time (RT) and signal-to-noise ratio (SNR) to see how they affected recall of words in Swedish (native tongue) and English. Participants were 72 children in the fourth grade who listened to wordlists presented in Swedish and English with broadband noise in the background. We compared two reverberation time (RT) conditions: a short RT (0.3 sec.) and a long RT (1.2 sec.), and two signal-to-noise (SNR) conditions: a low SNR (+3 dB) and a high SNR (+12 dB). Each wordlist had 8 words to be recalled. Main effects of language and SNR were found. Children could recall fewer words if they were presented in English or had a low SNR. Interactions were found between Language, RT, SNR and whether the words were at the beginning, in the middle or at the end of the wordlists. Recall performance was best with a short RT and a high SNR. Fourth graders recalled more words in their native language compared to English. Children might have difficulties with semantic association and understanding the meaning of words in English. Recall performance was markedly improved with good listening conditions, which indicates that there is something to be gained by improving the acoustical conditions in a classroom to improve memory and learning.