What you are describing sounds like an internal sound that you find pleasant while wearing headphones. It's important to note that meditation is a practice that encompasses various techniques and approaches, and experiences can vary from person to person. While there are meditation practices that involve focusing on sounds or using sound as a point of focus, such as mantra meditation or mindfulness of sound, it's best to consult with a meditation expert or teacher to receive guidance on specific meditation practices.
However, if you find that listening to the internal sound through headphones brings you a sense of calm, relaxation, or a meditative state, it could be a form of self-guided meditation or a personal relaxation technique for you. Exploring different meditation techniques and practices under the guidance of an experienced teacher can help you gain a deeper understanding of meditation and its benefits.