Best answer by DRSC Media
First, start by checking whether something is blocking the speakers. On the front of the device, and on the botton of it, you have speakers. It is not uncommon for dust or dirt to accumulate there. If you have a can of compressed air, it's easy to clean.
If this does not solve your problem, you can try a factory reset of the device. Make sure to properly backup all your data first.
Finally, if a factory reset doesn't fix the issue, I recommend you contact Huawei's Hotline to ask for more information on how to send your device for a repair.