Yes, Listnr is an allternative to Sound of Text, with a much bigger library of voices and a start of the art Text to Speech Editor, we're an option you must try! Here is a detailed analysis comparing Listnr with Sound of Text.
How much does Listnr cost?
Listnr is free for upto 1000 word conversions per month after that it costs $9/month for the Student plan, $19/month and so forth for other subsequent plans.
Can I cancel anytime?
Yes. If you want to cancel your plan, simply go to your profile and cancel in the account page. If you do cancel, you will continue to have access to all the premium features until the end of your billing cycle.