diff --git a/sys/src/9/port/audio.h b/sys/src/9/port/audio.h
new file mode 100644
index 000000000..42ab9712c
--- /dev/null
+++ b/sys/src/9/port/audio.h
@@ -0,0 +1,22 @@
+
+typedef struct Audio Audio;
+struct Audio {
+	Audio *next;
+	char *name;
+	void *ctlr;
+	void *mixer;
+	void (*attach)(Audio *);
+	long (*read)(Audio *, void *, long, vlong);
+	long (*write)(Audio *, void *, long, vlong);
+	long (*volread)(Audio *, void *, long, vlong);
+	long (*volwrite)(Audio *, void *, long, vlong);
+	void (*close)(Audio *);
+	long (*ctl)(Audio *, void *, long, vlong);
+	long (*status)(Audio *, void *, long, vlong);
+	long (*buffered)(Audio *);
+	int ctlrno;
+};
+
+void addaudiocard(char *name, int (*probefn)(Audio *));
+void ac97mixreset(Audio *, void (*wr)(Audio*,int,ushort), ushort (*rr)(Audio*,int));
+int ac97hardrate(Audio *adev, int rate);