Is it a factory radio? Or an aftermarket one?
They are usually two (or three) plugs in the radio. The two 8 pins are joint together. One of them is a power plug, the other is a speaker plug.
First, confirm that you have not muted the sound with a button on the radio or on the steering wheel.
Then check and confirm the speaker plug is properly connected to the radio. If it is, disconnect it, take a 4 or 9 V battery with some cables attached and plug it to each of the speakers terminals - to the positive and negative terminal of the same speaker - if the speaker is not damaged, it should make a buzzing sound.
It's rather rare, but might be that both (or all) speakers died.
If there's no buzzing sound, get to the back of each speaker and repeat the test. If you hear the sound now, it means there's a problem with the loom. If you don't hear the sound, it means the speaker is damaged.
If the speakers make the buzzing sound when you connect the battery on the back of the radio, this might mean that there's a problem with the radio itself.