"Authoritative voice" refers to a way of speaking or writing that conveys knowledge, expertise, and confidence. It is a tone that is convincing and persuasive, often used by someone who is seen as an expert in a specific field. Full definition
Rather than just following tradition or family customs, mothers were increasingly influenced by the strong authoritative voice of «science». (positive-parenting-ally.com)
Perhaps the most authoritative voices on the Common Core's effectiveness should be those of veteran teachers with hands - on experience about how students learn. (edutopia.org)