A:AnswerNo dont think you can sorry when you turn off the screen you also turn off the sound try the bose 300 soundbar you can do any kind of sounds example nature from youtube or amazon music
A:AnswerHi Kumar, The TV is designed to support 110 V – 240 V AC, 50/60 Hz (U.S.A./Canada 120 V AC, 60 Hz) and NTSC color system only. We can't guarantee that all its features would work since this is a US model. ~Ralph
A:AnswerHi Egde, It's Panel Refresh Rate is 120Hz. You may refer to this link for more information (Video Features):
https://docs.sony.com/release//specs/XBR55X900F_mksp.pdf
~Ralph