Voice on my computer

Help! My cat was laying on my computer this morning and when I shooed her off, there was a voice that suddenly appeared on my computer that seems to be narrating every action I take on the computer. Each box on the screen is outlined in black and the voice spells out each word I type or narrates the name of each application I select. I cannot figure out how to turn it off. Does anyone know what this is? I have no idea how the cat turned this thing on.

Thank you in advance.

 

Thank you

Thank you! That worked. I appreciate your reply.

Nancy