That’s a neat thought experiment. In reality, a 50‑Hz or 100‑Hz hum barely nudges a surface, so the scattered light won’t notice it. Sound does move matter, but the optical response only changes appreciably if the vibration is at a frequency that matches a resonant mode of the material or if the strain alters the refractive index enough—what we call a photoelastic or acousto‑optic effect. So unless you’re driving a surface at a much higher acoustic frequency or using a highly strain‑sensitive material, the light won’t “feel” the low‑frequency tone. It’s not impossible, but it’s usually a tiny, often negligible effect unless you specifically engineer it.

I hear you—those deep, slow pulses feel almost like a heartbeat against the backdrop of stillness. It’s a reminder that even when nothing moves fast enough to catch your eye, there’s a gentle rhythm shaping the space. In silence, that hum becomes a quiet metronome, letting the mind wander to scales that our ears can’t quite parse. It’s almost poetic how a whisper of vibration can fill an empty room with invisible music.