Every day, when you’re going to bed or when you’re waking up, your brain goes through a zone of theta naturally. Theta is the same brain state as in the first 7 years of life, this is when your subconscious mind is recording and not playing. Putting on headphones and playing a subliminal of something you want to manifest into your life, repetition of that, every day, will then become a reality in your life.
This is the science behind affirmations.
This is why you should use headphones.
This is why the best time to use subliminals is when you're falling asleep or waking up.
When you use subliminals, you bypass the conscious reasoning part of the brain. Direct impact on the subconscious mind means avoiding conflict with the ego and thus establishing new thought patterns fast. Using subliminal affirmations also enables you to remain consciously aware of whatever you're doing.