Why Your Sink Gurgles: What That Strange Noise Really Means

https://www.canberratimes.com.au/story/9118615/top-plumbing-warning-signs-you-shouldnt-ignore/

Gurgling Drains Are More Common Than You Think — and the Data Suggests Chemical Cleaners Cause More Harm Than Help The data suggests that noisy drains are not a rare nuisance