Abnormal howling like sound coming from system speakers when microphone volume is turned up

All ThinkPad systems with speakers located at the front edge of the bottom cover.

This issue occurs due to the Microphone Volume level in Master Volume being set to high.

Preventive measures:

• Turn down the microphone or speaker volume levels to avoid the howling sound.
• Open Volume Control>Option>Property>Play>Uncheck Microphone in order to hide Microphone in Master Volume.