Background: Bilingual (BL) listeners' difficulties in adverse noise conditions are exacerbated
when perceiving their second language (L2) relative to their first language (L1).
Perception of L2 is also significantly poorer by BL listeners compared to native monolingual
(ML) listeners.
Purpose: The purpose of the study was to examine the effect of stationary and nonstationary
energetic noise maskers on L1 and L2 speech perception in native and nonnative listeners.
Research Design: A mixed multivariate quasi-experimental design was employed.
Study Sample: Two groups of 12 ML English-speaking and BL Mandarin-English-speaking normal-hearing
young adult female volunteers participated.
Data Collection and Analysis: An adaptive technique was employed to determine reception thresholds for sentences
(RTSs) in quiet and in backgrounds of competing continuous and interrupted noise.
The noises differed only in their temporal continuity. The sentence stimuli employed
consisted of the Hearing in Noise Test (HINT) and the Mandarin Hearing in Noise Test (MHINT). ML participants received the HINT stimuli while the BL participants received
both HINT and MHINT stimuli. Between-group differences in RTSs were examined for the
same stimuli (i.e., HINT) and for L1 stimuli (i.e., HINT vs. MHINT). Within-group
differences in RTSs were examined with the BL participants' perception of L1 and L2
stimuli (i.e., MHINT vs. HINT). The amount of “release from masking” (i.e., the difference
of RTS signal-to-noise ratios [SNRs] in interrupted and continuous noise) was also
examined between and within groups.
Results: In quiet there was no significant difference in mean RTSs between the BL and ML participants
with their respective L1 stimuli; MLs had significantly lower mean RTSs in English
compared to the BLs; and mean RTSs for the BLs were significantly lower for L1 versus
L2 stimulus. In noise, a significantly higher RTS SNR was found for the MLs in continuous
noise but not interrupted noise for L1 stimuli compared to the BLs; BLs had a significantly
higher mean RTSs in English compared to the MLs; and BLs had significantly higher
mean RTSs for L2 versus L1 stimuli. The release from masking was significantly greater
for MLs compared to BLs with their respective L1 stimuli and with the same English
stimuli. There was no significant difference for the BLs' release from masking with
L1 versus L2 stimulus.
Conclusion: BL listeners display significantly poorer performance when perceiving nonnative L2
sentences in quiet and in continuous and interrupted noise relative ML listeners.
When listening to their respective native L1 sentences, only a difference in continuous
noise was found. This difference was attributed to differential masking effect on
the English stimuli. Similar performance in the interrupted noise between the ML and
BL participants with L1 stimuli and the equivalent release from masking with the BL
participants for both L1 and L2 stimuli suggest comparable basic auditory temporal
resolving capacities between these ethnic groups.
Key Words
Bilingualism - speech perception - noise
