The voice is indeed terrible, at least in my opinion. But there are alternatives that also offer more flexibility like adjusting the WPM. I can recommend speec

The voice is indeed terrible, at least in my opinion. But there are alternatives that also offer more flexibility like adjusting the WPM. I can recommend speechify. Their voices sound pretty good and the Browser extensions work well. The only thing I hate is how intransparent their pricing is. They do offer a free trial period. After that, their annual subscription is something like 140$. However, if you don’t decide to upgrade they will spam you with discount codes for 50% off which seems like a better deal.