In most cases, an IPX8 waterproof speaker can be used for showering, and it won't get damaged. However, you must be aware of one thing – If a device is IPX7/IPX8 waterproof, it doesn't have to be resistant to water jets or water splashes. So, an IPX8 waterproof device doesn't have to be IPX6 water-resistant. It can be, but it's not a rule. If a device is certified as both IPX6 water-resistant and IPX8 waterproof, you will see both ratings written in the specs list like this – IPX6/IPX8. That kind of device will most certainly be used in the shower.