/tags/%E5%A3%B0%E5%AD%A6/Recent content in 声学 on Mi&Bee BlogHugo -- gohugo.iozh-CN蓝宝石的傻话Mon, 04 May 2026 10:00:00 +0800/posts/physical-world/acoustics-dsp-basics/Mon, 04 May 2026 10:00:00 +0800/posts/physical-world/acoustics-dsp-basics/<h2 id="相消干涉">相消干涉</h2> <p>主动降噪（ANC）的物理基础是声波的相消干涉。两个频率相同、相位相反的声波叠加后会相互抵消。</p> <p>原始噪声信号：</p> <p>$$ p_n(t) = A \cos(2\pi ft + \phi) $$</p> <p>ANC 系统生成的反向声波：</p>