Dear Samsung Member,
Greetings from Samsung Customer Support!
To resolve "speaker" issue kindly follow the given below steps:
1) Check mute all sound option :-Settings >> Accessibility >> Hearing enhancements >> Disable Mute all sounds (if enabled).
2) Reset the device: -Kindly create data backup of your device via SMART switch mobile application or http://www.samsung.com/in/support/smartswitch pc suite.
Tap on Settings>Tap on General Management>Tap on Reset.
If the issue still persist, kindly register your concern in Samsung Members app (Samsung Members app > Get help > Feedback > Error report/ask question).
Note: Please send device log files within 15 minutes of issue occurrence along with the exact issue details.
Thank you for writing to Samsung.
Samsung Customer Support