DropdownList does not work very well with a screen reader.
It should work like this one https://www.w3.org/TR/wai-aria-practices-1.1/examples/listbox/listbox-collapsible.html
Using NVDA and Firefox, it reads the selected item 3 times, sometimes does not work at all (This is only when you open the dropdown using alt plus down arrow). Using just the arrow up and down keys does not work.
Using Cromevox and ChromeOn the dropdowns, it does not give a description of how many options are available like, "1 of 4" when you first tab to it. It reads it after I already selected the first option. That should be reversed, read the options first and not after its selected (This is only when you open the dropdown using alt plus down arrow). Using only the arrow key up and down it reads the selected item only but does not reads the other options.