Non-visual mind mapping alternatives

[Linux for blind general discussion]

I have just started taking an artist startup course. One of the early 
tasks involves making a mind map. I am aware that this is a highly 
visual exercise, but I am hoping that someone may have suggestions on 
non-visual alternatives to creating a mind map, specifically on either 
my Linux computer or my Android phone, although a web-based alternative 
would also be helpful. Thanks for any help.

~Kyle