If the laptop is under warranty, get this issue resolved from Acer support. Acer support team will try installing correct drivers and software for sound device in your laptop. If the issue is not resolving by installing drivers and software, the sound hardware (spare) will be replaced by the Acer support team on under warranty.
If the laptop is not under warranty, try below options.
1) Re-install sound drivers and software from your laptop and check the issue is resolving or not.
2) Re-install operating system and sound drivers in your laptop and check the issue is resolving or not.
3) Visit the nearest computer and laptop service center and get your laptop repaired on chargeable basis. This issue will surely resolve. Best of luck!!!.