Radiated sound depends on source area and air-displacement pattern, not just amplitude

Evidence

Some vibrating objects are very poor at creating sound even if they are vibrating with large amplitude in the audible 20 to 20,000 Hz frequency range. Others create regions of compression and rarefaction so close together that they nearly cancel each other. — Eric J. Heller, Why You Hear What You Hear- An…, 493

Categorization

• QUESTION: Which real objects are notoriously poor sound radiators despite large vibrations — worth chasing the acoustic-impedance mismatch explanation.