Accu-pitch is a feature found in the TU-15 that plays an audible "beep" when the instrument being tuned reaches the correct pitch. Use the following procedure to turn off the Accu-Pitch:
1. Turn OFF the power of the TU-15.
2. Turn the power ON while holding the SOUND button. (The current On or OFF status will show in the display for about 5 seconds.
Note: Repeat steps 1-2 to turn the Accu-Pitch on again.