Microsoft Edge
Right-click the PDF, choose Open with → Microsoft Edge, and press CtrlShiftU. Edge highlights the words as it reads. Its natural voices work online; offline it falls back to Windows' standard voices. More on Edge's Read Aloud.
Adobe Acrobat Reader
Choose View → Read Out Loud → Activate Read Out Loud (ShiftCtrlY), then Read This Page Only (ShiftCtrlV). It uses your computer's voices and works offline. It reads in the order the PDF's hidden tags give, so a paper without tags can be read straight across both columns.
On a Mac
Open the PDF in Preview and choose Edit → Speech → Start Speaking, or turn on Speak selection in Accessibility → Spoken Content, select a section and press OptionEsc. Download a Premium voice for a much better sound.
Apps made for papers
Services such as Listening and Audemic are built for academic PDFs, and some can skip citations and references for you. They work online, you upload each paper, and they're subscriptions.