James Clerk Maxwell (1831– 1879), was a Scottish physicist creating the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. His equations, layed the foundations for relativity, and quantum mechanics.

Oliver Heaviside (1850–1925) was a mathematician and electrical engineer who transformed Maxwell’s equations into the modern vector-calculus form, fundamentally shaping the modern interpretation and application. He also developed transmission-line theory and the skin effect, introducing much of the field’s core vocabulary, including conductance, impedance, and permeability. AT&T later utilized his work to usher in analog/digital telecommunications and sound transmission.

Sturm–Liouville theory is central to electromagnetic wave analysis: its eigenvalues determine resonant frequencies or propagation constants, and its eigenfunctions provide orthogonal mode bases. It is especially useful in Helmholtz separation, waveguide analysis, and cavity resonance.

Ohm's law of acoustics is a statement of the fact that the perception of the tone of a sound by the brain is a function of the amplitudes of the harmonics and not of the phase relationships between them. Characterizing the importance of timbre for human hearing, which is distinct from pitch and intensity. 

This law of accepted science was validated and expounded upon by the work of Dr. Hermann von Helmholtz.