The term "in voices" can be substituted with a variety of synonyms depending on context and tone. Some possible options include "in chorus," "collectively," "unanimously," "together," "with one voice," "as a group," "in harmony," "in unison," and "with agreement." These alternatives highlight the idea of multiple individuals coming together and expressing a shared sentiment or perspective. By choosing the right synonym for "in voices," writers and speakers can add nuance and emphasis to their language, conveying a range of emotions from enthusiasm to solidarity to conviction.