Or do they train with hybrid numeric piano. If they train using acoustic piano how do they prevent trouble with neighbours ?
Yes. As a professional, there's no way one could study on anything but a real piano.
A professional pianist masters the instrument in a way that to perform a piece giving it all he/she has in mind, a real piano will be needed, or the desired sound just won't be achieved.
That being said, if there are specific circumstances in which a pianist can't gain access to a real piano, some alternative may still be better that nothing, but that is some specific scenario which is very unlikely to happen to a professional pianist.
how do they prevent trouble with neighbours?
If they play for a living, which is the case you're asking, a professional pianist will have to find a way to prevent trouble with neighbous. That can include limiting practicing hours to hours when people don't try to sleep, somehow isolating the room where the piano is... Really depends on each case; the pedal options mentioned in some comments and answers are not really solutions. They may help some time, but it can't become a rule.
Hope this helps!
This site says:
Silent piano playing:
By pedaling and locking the middle pedal, a felt strip (moderator) between the strings and the hammer is lowered on acoustic pianos. The sounds sound softer, but also duller. Foot Coaster The structure-borne sound of a piano / grand piano can continue to spread over the instrument feet through the floor, walls and ceilings. Additional coasters with sound-absorbing inserts under the feet of the instrument provide an uncomplicated remedy. Soft piano playing with C. Bechstein Vario system So-called "silent systems" combine the performance of a normal piano or grand piano with a mute function and an electronic sound generator. So you can play on your piano at any time of day without disturbing your roommates and neighbors. Even for professionals with long overtime, this system offers an optimal supplement. The quality of the systems of different manufacturers is very different. Unstable stop bars and sensors can, when touched, affect the style and cause noise. Also in terms of sound and ease of use there are great differences in quality. With the first-class C. Bechstein Vario system you can extend your piano with the advantages of a digital piano: You get precise control over the high-quality Bechstein movement when playing the C. Bechstein Vario system. The hammers no longer hit the strings, but are intercepted by a switchable stop bar in the area of the mechanics. State-of-the-art optical sensors under the keys detect every nuance of the attack without changing the style. The authentically sampled sound of a C. Bechstein Concert Grand D 282 meets the highest standards when playing with headphones. Pedal function and sostenuto are retained All pedal movements are optically recorded with the C. Bechstein Vario system. In the Vario mode even a sostenuto function is available for the piano. Uniquely simple, convenient and intuitive, the system can be operated using the touchscreen from the game position. The C. Bechstein Vario system also offers numerous options for individual settings and adjustments that can be conveniently stored. Via the Midi connection of the Vario system, you can use the excellent style of a C. Bechstein game to control a wide variety of Midi applications on your computer or tablet.
You'll get opinions that 'classical' piano can ONLY be learnt on a real piano. But yes, the constraints of modern living make it necessary for a lot of students to practice on an electronic instrument. Not ideal, but inevitable. And you can learn a LOT of piano on them.
I wouldn't bother with attempts to dampen or isolate a real piano. They don't make THAT much difference. And a neighbour inclined to object to piano playing will still object if they can hear it AT ALL! I had a neighbour once who claimed to be disturbed by the keyboard clatter of an otherwise completely silent instrument.