Hey people, you realised that we may be talking too loud eh? But worry not. A Group of Understimated, Retarded Underagers (GURU) has a theory why our sound waves outright pwns their's.
First, there is the concept of 'IGNORE' (Interwoven Grounds Negating Oral Representation Effectively) and 'BLAME' (Blatant Lying About Making Explosions). According to GURU's theory, there is a layer of IGNORE between the 4D classroom and the 4E classroom which dampens sound waves created by the vocal folds of the 4E students. Only a certain teacher that has chemistry with sound has ever managed to perceive the narrow harmonic range that is not severely dampened. Even so, the second protective mechanism, BLAME, is present to ensure that the effects of their sound waves are negated.
Noteworthy is how ‘IGNORE’ functions like a partially permeable membrane, only sound from 4E undergoes dampening.
How ‘BLAME’ works remains puzzle brilliant minds all over the world. Here, we quote a recent interview with leading scientist L²M.
GURU: Thanks for taking the time to talk to us. What can you tell us about the current dilemma over the issue of ‘BLAME’?
L²M: Well, we are actually debating if the phenomenon is a result of 4E’s lack of scruples or common sense. In one notable instance when ‘BLAME’ was activated, they claimed that sound waves managed to pass through two layers of ‘IGNORE’ to reach 4D. This is obviously a very well coordinated scam or … you know.
GURU: You know…?
L²M: That they are plain retards. You didn’t have to make me say that didn’t you.
GURU: BWAHAHAHAH.
Moreover, there exist the ‘AMP’ (A Midgety Porcupine). This mystical creature shares similar traits as the legendary ‘草泥马’ in addition to the special ability to AMPlify noise and reacts by demonstrating the furthest extent in which the English language can be broken. The demonstration is usually accompanied by a spray of mouthly rain.
A simplified diagram of the above follows:

As usual, this post falls under the "we are talking about weird fantasies, stop linking it to real life you assholes" category and as such, all content is fictional and any resemblance to real-life events, people or mystical animals are purely coincidental. However, should you spot any resemblance, it isn't just you. (There may be monkeys, who knows?)
じゃね!
ー英語の達人。
Edit:
More advances in technology allowed GURU to single out the hormone that drives the AMP to such extremes. This hormone, tentatively named 'YATHEI' (Yet Another Tattling Headless Eminent Idiot), is supposed to drive AMPs into lengthy bitch fits. Methods to neutralise 'YATHEI' revolve around depriving its supply of 'CHONGYAN'(Carbon, Hydrogen, Oxygen, Nitrogen, GraYanotoxane and Norvalyl).