I assume you mean the BER from your transceiver. 0.9% BER is normal value in DMR - it won't be audible. Also note that the openSPOT4 calculates BER differently than MMDVM hotspots (and possibly IPSC2 servers).
You can test your own voice using the openSPOT4's built-in local echo service and also using the server echo, if it supports this (BrandMeister has a parrot feature). You can also try manually setting the RX offset value on the Modem page for the lowest BER.