As with the case of plant responses to different types of music being played, there's no definitive answer to whether plants grow faster because they're being talked to. The idea appears to be that plants may grow faster if people talk to them at close range.The reason tends to be twofold. One is that people expel carbon dioxide when they talk.Plants take in CO2, and release oxygen, as part of photosynthesis. So more CO2 helps photosynthesis, which leads to more energy reserves for plant activities, and therefore improved plant health.ctually, for carbon dioxide to even begin to affect the plant, you would have to talk to it for at least seven hours a day. Most scientists believe the reason talking and music help plants is because of the vibrations caused by sound waves or the pitch at witch you speak.