diff --git a/packages/dsp/src/osc/cos.ts b/packages/dsp/src/osc/cos.ts
new file mode 100644
index 0000000000..3d8b17e81b
--- /dev/null
+++ b/packages/dsp/src/osc/cos.ts
@@ -0,0 +1,5 @@
+import { TAU } from "@thi.ng/math";
+import type { StatelessOscillator } from "../api";
+
+export const cos: StatelessOscillator = (phase, freq, amp = 1, dc = 0) =>
+    dc + amp * Math.cos(phase * freq * TAU);