All turntables make noise to varying degrees, and we can hear it. That noise, however small, excites the stylus.
How small in practical terms? Well, I can hear the bearings in my 1.8W precision AC motor, whether the motor is energized or not. That’s with a 45kg platter.
As I understand it, ’lively’ is the opposite of ’dead’. I hear ’dead’ as resonance free, dull, which is bad in a piano and good in a turntable, I hear turntable ’liveliness’ as accentuated high frequency which makes everything sound sharp, as in jagged.
Every time I’ve made a big jump, like conventional bearings to air, or MM to Koetsu, the most obvious thing is a ’loss’ of high frequency. Then I notice that voices sound more like people I know, piano concerti sound more like the piano upstairs, and so on. It sounds ’dead’ for a few hours, and then I realize that it’s more natural.
But then again, that’s just my usage of the term, which may be idiosyncratic.