Who’s playing marbles at night?

It was the dead of the night. The sun had already melted down into inky blackness. As I went to sleep armouring myself from the buzz of the blood-sucking mosquitoes, something very sinister registered into my ears.

No, it wasn't the ominous ticking of the hands of the wall clock that sounded like a warning that an explosive is about to go off, rather some strange noises from my neighbours upstairs. Every other day, I hear my neighbour's children playing marbles on the floor right above mine. On top of that, they never seem to be satisfied with their furniture arrangement. The furniture-dragging noises surround me every time I close my eyes. What have they been up to? Unless…

If you have ever lived in an apartment in Bangladesh, you have most certainly heard these noises. The sounds of doors slamming, chairs shifting, and marbles dropping are so ubiquitous in the commotion around us that we don't stop to think where they are coming from.

Yes, it might have crossed your mind whether your house is haunted by the spirits of playful evil kids trying to get your attention. Though it may be a bit of a stretch, what else could it be?

The answer to this question is pretty simple. It is not all in your head, rather in your pipes! Hydraulic shock, also known as "water hammer", is a common occurrence in piping systems.

When the water flow inside the pipes is quickly changed or interrupted, a surge of pressure ensues, which hits the pipe walls. This produces noises by causing the walls of the pipes to vibrate. When you flush the toilet or turn off your tap abruptly, the water pressure changes and may result in hydraulic shock. The hammering and pounding noises from the pipes filtered through the cold, hard concrete may be mistaken for marbles rolling or furniture dragging.

Another apparent reason behind these clanks and bangs could be the air trapped inside the pipes. When these soapy air bubbles pop, they produce an echo that can imitate falling marbles. It takes a while for the water pressure inside the pipes to stabilise. So, the noise may be prolonged.

Furthermore, it might also be that the concrete and pipes in our buildings expand and shrink in summer and winter, which can give rise to such sounds. At night, the white noise around us dims down to some extent. As a result, these additional noises become more pronounced and eerie.

Sound travels, and just like ghosts, they deceive you into thinking that your upstairs' neighbours have gone into a frenzy. That's why, even if you live on the topmost floor, these "supernatural" sounds won't give you a break.

But then again, we can't fully rule out the possibility of it being paranormal, can we?

Farnaz Fawad Hasan is a disintegrating pool noodle wanting to stay afloat. Reach her at farnazfawadhasan@gmail.com