extern int register_sound_mixer(const struct file_operations *fops, int dev);
extern int register_sound_midi(const struct file_operations *fops, int dev);
extern int register_sound_dsp(const struct file_operations *fops, int dev);
-extern int register_sound_synth(const struct file_operations *fops, int dev);
extern void unregister_sound_special(int unit);
extern void unregister_sound_mixer(int unit);
extern void unregister_sound_midi(int unit);
extern void unregister_sound_dsp(int unit);
-extern void unregister_sound_synth(int unit);