Five letters create the qalqalah effect when they have sukoon: qaf, ta, ba, jeem, and dal. The sound bounces or echoes slightly.

When a qalqalah letter with sukoon appears in the middle of a word, it creates a small bouncing effect.

When a qalqalah letter with sukoon appears at the end of a word (especially when stopping, عند الوقف), the bouncing effect is more pronounced.