Noise, as part of real communication flow, degrades the quality of linguistic input and affects comprehender’s language processing. According to the noisy-channel approach and good-enough sentence processing model, noise makes people rely more on word-level semantics instead of actual syntactic relations when reading. To test that, this study analyzed the influence of auditory (three-talker babble) and visual (short idioms appearing next to target sentence on the screen) noise on sentence processing in two eye-tracking experiments. In both of them, we used the same stimuli - unambiguous grammatical Russian sentences - and manipulated their semantic plausibility. Our results did not reveal a greater reliance on good-enough processing under auditory or visual noise. On the contrary, reading implausible sentences under noise made participants concentrate on the critical region, read it slower and interpret sentences correctly in accordance with actual syntactic roles. We interpret this pattern as an example of more rational decision making under degraded linguistic input.