Concept:
In Indian musicology, sound is called Naad and is divided into two primary categories based on how it is created:
• Aahat Naad: Sound produced by a physical strike or friction between two objects (e.g., striking a drum, plucking a string). This covers all audible music and speech.
• Anahat Naad: Sound that exists without any physical contact, friction, or striking action. It is considered an eternal, cosmic vibration.
Step 1: Analyze the terms "Swayambhoo" and "Brahmandiya".
*Swayambhoo* means self-manifested or existing without external physical cause, and *Brahmandiya* means cosmic or universal.
Step 2: Match the description with the correct category.
Because Anahat Naad is an un-struck, eternal vibration that yogis and ancient texts describe as the underlying cosmic sound of the universe, it fits the description of being self-manifested and cosmic.