Krabok Siang Nam Lai (Bamboo Rain Tube) — Mature Bamboo 8-10 cm Across and 40 cm Long, Iron Spikes Set in Rings Down Its Length, Pebbles Inside, Woven Bamboo End Caps; Tip It and It Sounds Like Running Water

"How sweet the running-water sound is depends on the length of the tube; a long tube makes the sound last longer and sweeter." (Sirindhorn Anthropology Centre, author not named, CC BY 4.0)

Choose mature bamboo 8-10 cm across and about 40 cm long. Pierce iron spikes into the tube and leave them set in it, in rings running down its length.

Weave bamboo caps to close the two ends, closing one end first. Put pebbles into the tube, then close the other end with the second woven cap so the pebbles cannot fall out.

Decorate the outside with patterns.

Photos of a real rain tube (Sirindhorn Anthropology Centre, author not named, CC BY 4.0)

Tip the tube up and down; it sounds like running water.

Sound tubes like this imitate nature, and are found in Thailand, Vietnam and Indonesia. Take care with the iron spikes when piercing. Source: Sirindhorn Anthropology Centre, Traditional Objects of Everyday Use database, "กระบอกเลียนเสียงน้ำไหล", author not named (CC BY 4.0 licence). **Limits** The source gives no number or spacing for the spikes, no amount of pebbles and no decorating method. There is no product line for the iron spikes.