The Vedic syllable AUM is traditionally analysed as three phonemes—A, U, M—yet Indian philosophy has long described a fourth element beyond these audible segments. This paper reports a spectrographic observation of what occurs during the sustained nasal /m/ when chanted with deliberate articulatory awareness. Using VoceVista Video analysis of a single sustained vocalization (f0 ≈ 110 Hz), I document a continuous reorganization of the upper formant structure: F2 rises from ~600 Hz to ~2640 Hz, F3 rises from ~2500 Hz to ~3700 Hz, and the nasal anti-resonance—a traveling band of spectral silence—migrates upward from ~500 Hz to ~3000 Hz. These three trajectories converge at ~1800 Hz, where they encounter a steady peak (N3, the third resonance of the pharyngo-nasal tube), producing a brief deep attenuation before F2 recovers and continues upward. I distinguish this "living" /m/ from an "inert" variant with stationary spectral features. This acoustic contrast is offered, with appropriate humility, as a possible correlate of the traditional distinction between "struck" (āhata) and "unstruck" (anāhata) sound, and of the fourth element long described in the Upaniṣadic and Yoga traditions.