I like to silence my microphone on Roku

Do you have Hisense Roku TV?

Noted.
Do you want to disable voice narration on your Roku?

Please, follow the instructions below:

1. Press the Home button on your Roku remote control.
2. Navigate to Settings and select Accessibility.
3. Select Voice Narration and set it to Off. That’s all it!

• Enter the settings menu by pressing the Home button on your Roku remote and selecting Settings
• Navigate to the Accessibility section and select Voice Guide
• Select Off to disable voice narration

Do you have the * button on your Roku remote?

Noted that!

• Tap the star * button on your Roku remote four times to turn Screen Reader off.
• Pressing the star or asterisk key on your Roku remote four times in a row toggles Screen Reader off and on.

Could you tell me what entries are there in the ACCESSIBILITY submenu when you reach it?

Please press the Home button on your remote

Does it show you a menu with a SETTINGS entry in there?

There was no response to pressing the Home button?

By the way, can you find Options button on your remote?

Noted that, thank you for clarifying!
Okay, after you pressed Home button, can you select Settings sidebar on the left, and then select Accessibility?

Thank you!
Once you're in Accessibility menu, please, select Screen Reader > select OFF.

Is this issue settled?