Effect of Speech Degradation and Listening Effort in Reverberating and Noisy Environments Given N400 Responses
- Author:
Jeong-Sug KYONG
1
;
Chanbeom KWAK
;
Woojae HAN
;
Myung-Whan SUH
;
Jinsook KIM
Author Information
- Publication Type:Original Article
- From:Journal of Audiology & Otology 2020;24(3):119-126
- CountryRepublic of Korea
- Language:0
-
Abstract:
Background and Objectives:In distracting listening conditions, individuals need to pay extra attention to selectively listen to the target sounds. To investigate the amount of listening effort required in reverberating and noisy backgrounds, a semantic mismatch was examined.
Subjects and Methods:Electroencephalography was performed in 18 voluntary healthy participants using a 64-channel system to obtain N400 latencies. They were asked to listen to sounds and see letters in 2 reverberated×2 noisy paradigms (i.e., Q-0 ms, Q-2000 ms, 3 dB-0 ms, and 3 dB-2000 ms). With auditory-visual pairings, the participants were required to answer whether the auditory primes and letter targets did or did not match.
Results:Q-0 ms revealed the shortest N400 latency, whereas the latency was significantly increased at 3 dB-2000 ms. Further, Q-2000 ms showed approximately a 47 ms delayed latency compared to 3 dB-0 ms. Interestingly, the presence of reverberation significantly increased N400 latencies. Under the distracting conditions, both noise and reverberation involved stronger frontal activation.
Conclusions:The current distracting listening conditions could interrupt the semantic mismatch processing in the brain. The presence of reverberation, specifically a 2000 ms delay, necessitates additional mental effort, as evidenced in the delayed N400 latency and the involvement of the frontal sources in this study.
