Update Configuration.h

documentation how to disable buzzer feedback

Marlin/Configuration.h

 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
 //#define ULTIMAKERCONTROLLER //as available from the Ultimaker online store.
 //#define ULTIPANEL  //the UltiPanel as on Thingiverse
-//#define LCD_FEEDBACK_FREQUENCY_HZ 1000	// this is the tone frequency the buzzer plays when on UI feedback. ie Screen Click
-//#define LCD_FEEDBACK_FREQUENCY_DURATION_MS 100 // the duration the buzzer plays the UI feedback sound. ie Screen Click
+#define LCD_FEEDBACK_FREQUENCY_HZ 1000	// this is the tone frequency the buzzer plays when on UI feedback. ie Screen Click
+#define LCD_FEEDBACK_FREQUENCY_DURATION_MS 100 // the duration the buzzer plays the UI feedback sound. ie Screen Click
+                                               // 0 to disable buzzer feedback  
 
 // PanelOne from T3P3 (via RAMPS 1.4 AUX2/AUX3)
 // http://reprap.org/wiki/PanelOne