Practicing can be a lot of different things. One of the things it is not, in my opinion, is a concert or performance for anyone nearby.
Why not, and why bother saying so?
Because I believe that the rawness of practicing and the sacred nature of the time we spend doing it are worth preserving and cultivating. To that end, we need to know (and those around us need to know) that practice is its own different, special thing.
Raw, because you're trying things out, many of which won't be immediately successful. In addition, some things could be considered downright ugly when practiced well: vibrato is a good example. Others, such as certain bow strokes, fast complicated passages, or large shifts, require taking risks and playing with a certain abandon that takes no heed of how you might sound. In other words, you need to be able to jump, knowing it's fine if you fall.
Some things just take a really, really long time to get.
Raw, because so often practice is a process of taking things apart and breaking them down into their essences. If I'm working on the bowing in a certain passage, I won't be concentrating as closely on my intonation. If I'm working on my intonation, I'm not always playing in rhythm or in tempo. Practice regularly consists of small bits of music played over and over in a way that makes something -- physical, emotional, or musical --- clear to me in a way that maybe only I understand. This is raw beauty, but not always externally pleasing.
Which brings me to the sacred nature of practice (I use an extended meaning of the word 'sacred', having to do with reverence and dedication). During practice, we play, listen to ourselves, ask ourselves questions, propose solutions, play, listen again. It's a time of self-communion. It's a time of exploration, refinement, expansion, and empowerment. Practice strengthens your connection to your own voice.
This is true no matter how old you are or where you are in your musical development. As soon as possible, I start working with my students to put them in charge of what and how they practice. We check in each week, clarify what needs clarifying, work on what needs work. We talk, in various ways, about time management and schedules. We acknowledge the mental and emotional energy involved in practicing, and examine what can sometimes make it hard to find or invest that energy. This process sets the groundwork for a longterm relationship with practicing. It also gives the practicer a vital guiding role in determining what they value in their playing, and how they aim to pursue and cultivate it.
Of course it's nice to be heard and complimented on your practicing. I love it! Maybe you're lucky enough to have a supportive parent, roommate, or partner who is able to give you positive feedback or guidance as you practice. I still encourage you to set aside some of your practice just for yourself. Some things really are meant just for you. Some problems can teach you only if no one but you is there to fix them; some victories carry their full power only when you're truly the first one to take them in and celebrate them.
