Siri doesn't respond to "Hey Siri" whether my iPhone is unlocked or not

Hello sdevgupta,

We have a great support article that might help with this. It looks like this was linked to your posting. Were you able to review it? If not, please take a look at it here: If "Hey Siri" isn't working on your iPhone - Apple Support. Follow this guidance:

"Check if "Hey Siri" is turned on

1. Go to Settings.
2. Tap Siri & Search.
3. From here, make sure the following settings are turned on:

• Listen for "Hey Siri"
• Allow Siri When Locked

Set up Siri to recognize your voice

1. Go to Settings.
2. Tap Siri & Search.
3. Turn off Listen for "Hey Siri," then turn it back on.
4. When the Set Up "Hey Siri" screen appears, tap Continue.
5. Say each command that you see on your screen.
6. Tap Done.

If Siri stops responding

1. Go to Settings.
2. Tap Siri & Search.
3. Tap Siri Responses. 
4. Tap Prefer Spoken Responses to hear Siri speak responses, even when Silent mode is turned on.

Get more help with Siri

• Is the wrong device responding to "Hey Siri?" Learn how "Hey Siri" works with multiple devices.
• Learn how to change the volume of Siri's voice.
• If Siri activates when you press the side or Home button, but doesn't activate when you say "Hey Siri," contact Apple Support."

If the issue persists, further assistance may be needed. We want to make sure you reach the right team for help with your iPhone & Siri, so we recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support - Apple.

Thank you for participating in the Apple Support Communities and have a wonderful day.