"united voice" is correct and usable in written English.
You can use it to refer to a group of people voicing their opinion together. Example: The crowd chanted in a united voice in support of the protest.
"This is the people speaking with a united voice".
If we had one united voice, we'd play a much bigger role in public debate.
"The countries of the European Union need to speak with a clear and united voice.
Culturally, too, the Europeans see their influence in the world as a product of their united voice.
If Asia is to avoid a repeat of historical pitfalls, it must forge regional cohesion and speak with a louder and more united voice.
It's a forum where you can decide your priorities as owners and discuss how to speak to the board and management about these priorities in a united voice.
They have them in Germany". Everybody might agree about lorries, but our readers speak with a less united voice about using headlights or running lights in daylight.
But the UWM-button wearers assert that the two unions can speak with a united voice without carrying out a complicated merger.
A co-ordination council has been formed, Amir-Arjomand said, which aimed to create a united voice for the movement's leaders and activists.
What's needed is the gift of a powerful and united voice for social care, including on equal terms frontline workers, service users and family carers.
"In one united voice," Mr. Levin said, "we must not only condemn these acts of violence that terrorize Americans every day, we must act against them.
