My puppy Xena (4 months) was scared of the blender too at first. When I put it on she was just outside relaxing and got a huge fright. After that if I brought it near her she would back away scared.
To help overcome her fear I would place the blender on the ground and with Xena leashed. I then would reward her for coming closer and closer and I would ignore any scared behaviour. After she got good at being around it I started to turn it on at the same time rewarding her.
After persisting at this she is now ok around the blender. But I still never put it on if she is nearby resting.
Hope I helped!