If you had previously installed BBS sounds do a complete clean install of the aircraft. If not, just switching XPRealistic off won't solve a problem if it causes one. You need to remove it from the Plugins folder before starting X-Plane. In general, if you have a problem with an add-on that others don't have, then it is most likely due to your configuration. Therefore, to find out what causes the problem do the following:
1) remove all 3rd party plugins from the plugin folder and restart X-Plane. If that resolves the issue you know it is one of the plugins you removed.
2) Add them back one by one and observe when the problem comes back. Then you know what causes the problem.
If removing all 3rd party plugins doesn't resolve the issue then it is either a X-Plane setting that interferes or a setting in the aircraft itself.
3) In that case I would look into sound settings in both X-Plane and the aircraft.
iMac5K 27” (2015), i7 4GHz, OSX 10.14.6, 32GB, AMD M395X 4096MB, Saitek X52, TPM, Radio, Switch & Multi, TM MFD, XP11.35r1, FFA320v0.11.2-2305, ToLiSs A319 v1.3.3, JDA320 v3.4r1, JDA330 v3.2r1, XL v4_250719, FM v2.6r2, GndHdg v.4.010719, Air Plugin v4.8.3, FWL 2.7.19, 3jFPS-wizard, PI v2.73.06, NOAA v2.4.4, XSPs v2.75, XCL v1.37, BPB v0.47, SAM 1.1.0