A horn’s main benefit is source loading, not directional aiming.

Evidence

As was stated in a scholarly paper by A. G. Webster in 1919, when such phonographs were still in regular use, “it is well known that very little sound is emitted by the phonograph … with the horn taken off, although in the former case the motion of the diaphragm is exactly the same.” This is an important point. The action of the horn is not somehow to make the diaphragm move more vigorously; rather, the diaphragm motion is the same. More power is produced because of the presence of an enclosing chamber and the horn that leads from it. The former resonantly loads the source; the latter gets the sound out with minimal reflections. — Eric J. Heller, Why You Hear What You Hear- An…, 539 (#corroborates, via linked claim)

Categorization

• XREF: connects to: Concentrating sound into a smaller solid angle raises horn sensitivity; A horn amplifies sound without increasing diaphragm motion — Eric J. Heller, Why You Hear What You Hear- An…, 539; Horns and boundaries both concentrate sound into restricted solid angles

Related

• A horn amplifies sound without increasing diaphragm motion (similarity 0.92)
• Horn loudspeakers amplify sound through proximity resonance in a narrow throat (similarity 0.85)
• Horn throats boost output by constructive interference with the source (similarity 0.85)
• Horn confinement amplifies siren output via proximity resonance. (similarity 0.83)
• Horns and boundaries both concentrate sound into restricted solid angles (similarity 0.83)
• Concentrating sound into a smaller solid angle raises horn sensitivity (similarity 0.80)
• Horn confinement forces air bursts to do more acoustic work (similarity 0.80)
• Constant-directivity horns are efficient but cannot cover frequencies below 500 Hz (similarity 0.80)
• Horn size physically constrains the frequency range of directional coverage (similarity 0.80)
• Nearby reflective surfaces can load a source and boost its output (similarity 0.79)
• Passive devices and even walls can amplify sound without power (similarity 0.79)
• A diaphragm loading the bridge drives the Stroh violin’s horn (similarity 0.79)
• Stroh violins were invented to direct string sound into early recording horns (similarity 0.78)
• A speaking horn’s distant source location distorts vowel-forming resonances (similarity 0.78)

Broader Connections

• A horn amplifies sound without increasing diaphragm motion #corroborates (0.90) — Eric J. Heller, Why You Hear What You Hear- An…, 539
• Concentrating sound into a smaller solid angle raises horn sensitivity #expands (0.85)
• Horns and boundaries both concentrate sound into restricted solid angles #corroborates (0.80)