A brass bell reflects sounds selectively by frequency

Evidence

A Helmholtz resonator is a cavity-type resonator, so constructed that it will vibrate only at a particular frequency. It was developed by the German physicist Hermann Helmholtz in the nineteenth century to analyze the harmonic components of complex sounds. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 920 (#expands, via linked claim)

Categorization

• XREF: connects to: A trumpet’s bell beams high frequencies forward, changing timbre with direction of aim. — Eric J. Heller, Why You Hear What You Hear- An…, 1532; The bell acts as a frequency-dependent reflector that shifts brass mode frequencies.; A resonant cavity can isolate a single frequency from complex sound. — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 920 (+1 more)

Broader Connections

• A resonant cavity can isolate a single frequency from complex sound. #expands (0.92) — Schafer, Murray R, The Soundscape- Our Sonic Environment…, 920