The WetVac offers many different voice prompt languages that the user can select from. In addition, the voice prompt volume can also be adjusted according to the user's preferences. Please refer to the following detailed instructions:

How to Select Voice Prompt Language:

1. Gently step on the foot pedal and pull the handle bar backward until you hear a click.
2. Press and hold the water spray button with one hand, then hold the self-cleaning button with the other hand to enter language selection mode.
3. Press the water spray button repeatedly to select from the available languages.
4. When you hear the desired language, press the high/low button to confirm. The selected language will be saved.

How to Adjust Volume:

The voice prompt defaults to a low volume level. Press and hold the self-cleaning button for 3 seconds to adjust the volume level or turn off the voice prompts. 
 

Here is the picture showing the location where to adjust the volume:

Here is a video for reference: eufy Clean WetVac W31: How to Select a Voice Prompt Language and Adjust Volume

If you have any additional questions, please contact eufy support for assistance.