The phrase "gentle vibration" means a soft and subtle shaking or trembling sensation.
Sentences with «gentle vibration»
Setting this «silent alarm» of sorts wakes you up with gentle vibrations that won't disturb anyone else. (techradar.com)
Other touch stimuli, such as gentle vibrations, gave similar results. (newscientist.com)
And this summer, «smart» gear — or clothing that encourage proper form and focus on specific areas through gentle vibrations — are front and center. (mindbodygreen.com)