The Sound Breathing combat and breathing style mimics sound waves, specifically its disorientating loudness, and replicates it if the user's movements, techniques and swordsmanship. Most, if not all, known techniques and forms utilize an object that creates huge amounts of sounds and uses that as a powerful attacks and effective confusion to close in, as well as extremely fast movements similar to how fast sound travels and the sense of hearing. If used correctly, the user visualizes amber sound waves emanating from their weapon or parts of their body.
The only known user, Tengen Uzui uses a battle strategy called a "Score", which involves Tengen using his incredible hearing reading his opponents movements and deconstructing them into sound by analyzing the rhythm of their movements. Through this, he is able to take advantage of their openings to much greater effect by striking in a way similar to making the beat to a song. His combat style focuses on generating huge amounts of sound to overwhelm his opponents. In conjunction with this, he uses small but powerful anti-demon bombs made with a special gunpowder that are capable of overpowering an Upper Rank Demon briefly, and uses his sound abilities to make sure there is no collateral damage on humans when throwing them out of his line of sight.
Since this combat style can only be used by Tengen, it can only be used with a specific set of weaponry, which is two larger-than-normal Nichirin Blades, which each have a notch in the sharp ends of their blades and are held together at the hilt by a metal chain. His swords are said to have large amounts of explosive power, and it is stated that, until Tengen's fight with Upper Rank 6, no one had ever survived a blow from them.
First Form: Roar (壱ノ型轟, Ichi no kata: Todoroki?) - Uzui lifts his twin swords above his head and slams them down with great force whilst simultaneously creating an explosion with his bombs, causing a loud sound resembling thunder.
Fourth Form: Constant Resounding Slashes (肆ノ型響斬無間,Shi no kata: Kyōzan Muken?) - Uzui holds his swords apart and spins them rapidly in conjunction with releasing his bombs, making this technique a combination of offense and defense.
Fifth Form: String Performance (伍ノ型鳴弦奏々,Go no kata: Meigen Sōsō?) - Uzui holds one of his swords with a reverse grip and spins the other using the chain that connects them. He couples this by also releasing numerous bombs to detonate. This technique was able to overpower an Upper Rank Demon.