The TalkBack voice output can be adjusted on the LG smartphone, and in addition to the language, the speaking speed and pitch can also be adjusted.

Android 9 | LG UX 9.0
Step 1:  Open the  Settings
Step 2:  Tap on  General
Step 3:  Tap on  Accessibility
Step 4:  Tap on  Vision
Step 5:  Tap on  TalkBack
Step 6:  Tap on  Text-to-speech output
Step 7:  Move Slider to adjust  Output
  1. Open the Settings
  2. Tap on General
  3. Tap on Accessibility
  4. Tap on Vision
  5. Tap on TalkBack
  6. Tap on Text-to-speech output
  7. Move Slider to adjust Output

LG Instructions