The roaring sound from a cat’s chest is usually the sound of snoring. It will make this sound when the cat feels happy, relaxed and comfortable. It is a normal phenomenon; you can stroke the cat’s head, chin or gills, so the cat will feel more satisfied.
Tips:
Cats may also make this sound when they are feeling unwell, so you need to observe if the cat often If it makes noise for no reason, it is best to send it to the pet hospital for examination.