"public speeches" is correct and usable in written English.
You can use it when referring to speeches delivered to the public. For example: "I wrote a speech to deliver during my public speeches."
His public speeches set endurance records.
Because the public speeches just seemed to polarize everyone.
Sparpolitik, or austerity, has virtually vanished from her public speeches.
Some have thrown hand grenades during public speeches.
When he gives public speeches, he often wears a sweatshirt.
In contrast to her flat judicial writings, Sotomayor's public speeches are full of hyperbole.
Mr Assad did not even give any public speeches during his election "campaign".
One scans her public speeches looking for a strong opinion, and one comes up empty.
He tapped Democratic anger and attacked General Orders 38 in public speeches.
George Pullman prohibited independent newspapers, public speeches, town meetings, or open discussion.
He has delivered at least two public speeches, something his reclusive father never did.
