Please refer to the earlier post for details on rule #8
Crash has always struggled with the mechanical noise (a blender, vacuum, fan for example). When he was younger he would scream at the top of his lungs and covered his ears when these daily sounds would occur in his presence.
All though he has become desensitized to these sounds, his primal reaction still remains. My house still needs to be cleaned, food still needs to be prepared, and humidity needs to exit the bathroom. So what do we do?
In the case of the first two, we warn Crash ahead of time that the noise is going to occur. With this advanced warning he is able to tolerate the auditory insult. We used to have him pick a "safe spot" in the room that he would like to sit in before the noise began, but we no longer have to do this.
In the case of the bathroom fan, I had just gotten lazy and forgot to turn it on for a while during bath time. We warned him the next day that the fan would be on when he got to the bathroom. He wasn't happy about it, and took the fastest bath in history, but tolerated the noise enough to complete his task. He will still acknowledge his dislike of the sound but bath time has gradually been getting longer. We acknowledge his dislike, and explain why it is necessary to run the fan.