Hi, my ear speaker is not working. what might be the issue

Have any parts of the hardware been replaced lately, for example the display?

If not, try the troubleshooting mentioned in the related article:

If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support

In case this does not solve the issue, your device has to be checked by Apple or an authorised Apple Service Provider next to your place:

Apple - Find Locations

iPhone Repair & Service - Apple Support

The link on top of this page which you had visited, before posting this question here, is shown under the "Related Article” that may have given you an answer.

You need to mention which part of the article was not clear to you.

With the limited information that you have provided, It is hard to even guess the problems faced by you. 

You may get faster and better responses to your query by --> Writing an effective Apple Support Commun… - Apple ...

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