On a scale from a happy cat's soft purr, to your phone vibrating in a bucket of nails t, Lioness is a 3 (very scientific scale).

In all seriousness, the Lioness vibrator has a very strong motor that is very quiet when compared to other vibrators of comparable strength.

Furthermore, you can customize the strength of your vibrator to your fancy on a scale from 0 to 100. The stronger the vibration, the louder it gets. You can adjust the vibration strength to suit your situation (Parents in town? Roommate next door? Kids sleeping? Turn it down).