The reasons why your cat at home may come and purr at you when it hears you singing may be as follows:

1. The purring sound made by cats is caused by the vibration of their false vocal cords.

2. When a cat purrs, the vocal cords and false vocal cords vibrate at the same time, so the cat’s purring is a kind of purr produced by the vibration of muscles and false vocal cords.

3. When cats are anxious, uneasy or dangerous, this sound can relieve cats' anxiety and tension, making them feel relaxed and comfortable.

4. The cat’s purring also has antibacterial, antidepressant and anti-shock effects, so this sound may be the cat’s special response to its owner.

The above information is for reference only. For more information, please consult your veterinarian.