Talk to Speech (TTS) Converter

Good afternoon, fellow web managers.

I am interested in using Feedblitz for email subscriptions to our feeds.  They use a captcha for registration; however, it is not Section 508 compliant.  Visually impaired users would have to contact technical support.  I feel that is an undue burden on our disabled users. 

 

Feedblitz has suggested we use a TTS converter.  Is anyone familiar with this tool and do you have any suggestions?

Thanks in advance.