The essential founding principle of liberal society is free speech, the ability to express oneself openly without retribution or permission from the government. In America, and many other nations, it is a constitutional right. Those same nations also commonly regulate sound through volume restrictions and noise permitting processes. This paradigm shattering text argues that sound is an essential component of free speech, central not just to forms of creative expression like music, but to political speech and economic self-reliance, and that sound's restriction and regulation through noise codes is an unconscionable infringement on human rights. It details how seemingly innocuous noise codes create ripple effects across class, race, public safety, police misconduct, the environment, the economy, and more, further oppressing the poor and rotting democracy from the inside. Both a nuanced philosophical exploration of sound as a political concept and a call to arms, The S.O.U.N.D. Manifesto shows that nearly everything the public believes about sound is backwards-and just what it will take to make our speech truly free. And once you've read it, there's no going back.