If you are able to highlight the text in the PDF one word at a time then you may be able to have it read aloud the Adobe Reader 'Read Out Loud' tool. Unfortuantely this may not work with all PDF files as it depends on how the PDF was orginally created.  You may be able to use SensusAccess to convert the PDF into a tagged PDF which may allow the text to be read aloud.

'Read Out Loud' works best when the 'Reflow' setting is switched off. To switch off 'Reflow':

1. In the current version of Adobe Acrobat Reader click on Menu, then Preferences.  Alternatively press the shortcut key CTRL+K  

OR in older versions of Adobe Acrobat Reader click on the Edit menu, then Preferences

2. Choose the Accessibility category.
3. Untick the box next to Always use Zoom Setting.
4. Then close and re-open your PDF document.

You must then activate Read Out Loud before you can use it.

Activate Read Out Loud on

1. In the current version of Adobe Acrobat Reader click on Menu, then View

OR in older versions of Adobe Acrobat Reader click on the View menu. 

2. Choose Read Out Loud.
3. Then Activate Read Out Loud (or press Shift+Ctrl+Y).

Change reading voice

1. In the current version of Adobe Acrobat Reader click on Menu, then Preferences.  Alternatively press the shortcut key CTRL+K

OR in older versions of Adobe Acrobat Reader click on the Edit menu, then Preferences (at the bottom of the menu).

2. Choose the Reading category.
3. Remove the tick from Use default voice
4. Choose a voice from the Voice drop down list – the list of voices available to you will depend on what you have installed on your PC. ScanSoft Daniel is a good voice.
5. Click OK

Read a PDF

1. Go to the page in the PDF you want to read.
2. In the current version of Adobe Acrobat Reader click on Menu, then View

OR in older versions of Adobe Acrobat Reader click on the View menu.

3. Choose Read Out Loud then: 

• Choose Read This Page Only (or press Shift+Ctrl+V). 
• Or choose Read To End Of Document (or press Shift+Ctrl+B).

If you hear the message "Warning - Empty page", please make sure the Reflow setting is switched off, as above.

Stop reading out loud

1. In the current version of Adobe Acrobat Reader click on Menu, then View

OR in older versions of Adobe Acrobat Reader click on the View menu.

2. Choose Read Out Loud then: 
3. Choose Pause (or press Shift+Ctrl+C). 
4. Choose Stop (or press Shift+Ctrl+E).

Switch Read Out Loud off

1. In the current version of Adobe Acrobat Reader click on Menu, then View

OR in older versions of Adobe Acrobat Reader click on the View menu.

2. Choose Read Out Loud.
3. Then Deactivate Read Out Loud (or press Shift+Ctrl+Y).

What to do if it doesn't work

Unfortunately, this may not work with all PDF files as it depends on how the PDF was originally created.  You may be able to use SensusAccess to convert the PDF into a tagged PDF which may allow the text to be read out loud.