Impedance discontinuities split an arriving wave into reflected and transmitted parts

Evidence

If the cross-sectional area or any acoustic parameter of the medium in a tube changes at any position so that the acoustic impedance Za changes, the simple propagation of a wavefront is disturbed. At such a discontinuity, an arriving wave is split so that part of it reflects back and part of it propagates through the discontinuity. … From Equations (2.25)–(2.27), it can be concluded that if Z1 = Z2, which means that there is a perfect impedance match, the reflection coefficient R = 0 and no reflection occurs. If impedances Z1 and Z2 are very different (impedance mismatch), a strong reflection occurs. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 235

Categorization

• DEFINE: Impedance mismatch as the governing principle of reflection — foundational to understanding horns, ear canals, and architectural acoustics.
• corroborated: 2 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 235
• XREF: connects to: Superposition of imploding double-layer plane waves explains why cone reflection flips pulse phase; Anti-reflection coatings work by breaking impedance mismatch into graded steps; Waves split into reflected and refracted parts at impedance-mismatched interfaces (+6 more)

Broader Connections

• Waves transitioning from bounded to unbounded space create interfering reflections #expands (0.85)
• Bounded sound waves change impedance with tube area, causing reflections #exemplifies (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 174
• Perfect impedance matching eliminates reflection while mismatch causes it #expands (0.85)
• Acoustic impedance mismatch determines both reflection phase and magnitude #expands (0.85)