V'anisa v'amarta. Rashi saus bkol ram.
Strange sifri. Mikan amru that at first those that could would say and the others, someone read for them...
How is this mikan amru?
Chanukas hatorah connects this Rashi with the next - arami oived avi - by asking how can one raise his voice - isnt that a display of k'tanei amunah? He answers with the next rashi tgat lavan thought to destroy... Since we are mentioning Hashem's knowledge of a person's thoughts its obvious we're not raising our voices due to lack of emunah.
Id like to offer another answer. Only by tefilah is it an issue. But when we praise Hashem, like the ramban says the institution of batei knesios is to publicly announce 'briosecha anachnu'!
Based on this perhaps we can say that here the kol ram is me'akev. So the sifri says mikan amru - since it must be aloud, one who could say it
Aloud would but if he
Couldn't, someone who can say it loud had to read for him even if the person was able to read. The loud proclamation had to be.
May Hashem give us a lot to praise him for very loudly
