Assuming that boys are socialized to be more confident, bold, and outspoken, the end result is that men will end up talking over women. In an open forum setting, such as a professional or educational one, when the floor is open to anyone, it seems like men are more likely to speak up first.
Part of me thinks, "Well, anyone can speak if they wanted to! If I can count to ten and still be the first to talk, then so be it!" But part of me also wants to help uplift others and give them a chance to speak.
To me what stands out is not the fact that men speak up more than women do, but that women get ignored/dismissed when they do speak. I make an effort to:
Give them attention
Understand their point of view
Engage in their point of view
Not let others (men) interrupt and if they do, quickly get back to the core discussion until the speaker is satisfied/has said everything they wanted to say
Basically give your attention not to the loudest ones, but the ones that deserve it. Things like these make all people who usually don't engage in discussions more likely to engage in the future.
I think you are absolutely right. In general I think that everyone should feel comfortable to speak when they want but in return should respect that other people get the right to have their voice heard too.
When dealing with small groups, I ask participants for their perspective by name. The loudest doesn't go first, and everyone gets equal-ish time. That doesn't scale to a large forum though.
It's not just a gender thing, it's also a family/culture thing. Like I just come from a family where people will talk over each other, but than I have some balkan friends who will talk over me like it's nothing (no matter the gender). What I try to do is to adjust to the situation - if someone is quieter I will let them speak out, if someone is interrupting I will also join in in a more lively way. In a group setting if I see that someone is getting talked over - I will try to refer the conversation back to them.