90% confident that it will have a negative impact. A lot of learning comes from the ability to feel the keys/hammer, and to control how much / fast to strike them. Your reactions / responses are according to what you heard, and you train your muscles memory based on these. Unless the training is purely for getting notes right, at the stage where expression doesn't matter, and just accuracy matters.

Albert and Soo Hin, thanks for sharing your thoughts! I have the inkling that the current situation is not ideal but unfortunately, it is unlikely to change. I love my upright and would like to keep it in its original form. :)

Will keep the muted practice for getting the notes right or for loud passages. I agree that the softer/more delicate passages should not be practiced with the muted pedal at the first instance. If the passages are meant to be soft, I think it is still ok to practice without the muted pedal even at 10+ pm or 11 pm. :p

Wow, thanks Zensen! That's very comprehensive. ?? I have mixed feelings la. For me, it's good to start playing casually. But if I can progress well (god knows), might as well take some exams to prove something? Definitely not to become concert pianist like you mentioned. I'm working, so, being able to play at night is a big deal to me, cos that's the time I probably can practise (I hope so!) ?

That being the case, I'd recommend that you start small by buying a digital piano. If space or mobility isn't a constraint for you, I'd recommend a full-fledged one with 88 keys. Depending on your budget, a high-end one costs S$2,699 while an entry-level one costs S$700. Mid-range will be around S$1,699. But if you are space-conscious and prefer it to be more mobile (so that it can be moved around easily), then I have a 76-key version ($400+) and a 61-version (also $400+) to recommend for you. If you are ultra-budget conscious, it will be $269.

61 keys (5 octaves) is really the minimum you should start with. This is because any shorter (e.g. 49 keys, 4 octaves) won't allow you to play it with both hands (meaning right hand on melody and left hand on bass and chords). Also, you'd need to look for a model that has touch response/touch sensitivity. This is because some very cheap ones don't come with this, thus no matter how soft or hard you strike the keys, the volume/loudness is the same, which makes the music you play sound monotonous/robotic/expressionless!