int AUBeep(void);                                   // Play beep sound
int AUTone(int freq, int time);                     // Play tone with FREQ for time/100 sec
int AUCheckTone(void);                              // Non-blocking test if tone has finished
int AUPlay(BYTE* sample);                           // Play audio sample
int AUCheckPlay(void);                              // Non-blocking test if playing has finished
int AUMicrophone(void);                             // Return microphone A-to-D sample value
int AURecord(BYTE* buf, int time, long freq);       // Record sound for time/100sec using sample FREQ
int AUCheckRecord(void);                            // Non-blocking check whether recording has finished