this is something you need to discuss with your doctor whom i hope is a neurologist.
i have freezing episodes when i don't take my meds on schedule and sometimes my medication, carbidopa/levodopa, just doesn't work. i think all pd'ers eventually experience this. when my medication isn't working i have a more difficult time talking but i can talk. this started maybe 10 years after diagnosis.

but again, you need to talk to your doctor.