Positive feedback drives the reed to slam shut

Evidence

The gap between the reed and shallot is narrow, and for air to flow there must be a higher pressure in the boot than in the shallot, which tends to close the reed fractionally, resulting in the gap between the reed and shallot being narrowed. When the gap is narrowed, the airflow rate is increased and the pressure difference which supports this higher airflow is raised. The increase in pressure difference exerts a slightly greater closing force on the reed, and this series of events continues, acceler­ ating the reed towards the shallot until it hits the edge of the shallot, closing the gap completely and rapidly. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1227

Categorization

• XREF: connects to: Pressure feedback drives the reed into full closure across each cycle — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1198; Reed oscillation is self-sustaining through a positive feedback loop of airflow and pressure — David Howard, Jamie Angus, coustics and Psychoacoustics, 1227; Reeds must vibrate faster than the air column to reinforce resonance — Eric J. Heller, Why You Hear What You Hear- An…, 1613 (+1 more)

Broader Connections

• Reed oscillation is self-sustaining through a positive feedback loop of airflow and pressure #corroborates (0.92) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1227
• Pressure feedback drives the reed into full closure across each cycle #corroborates (0.90) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1198
• Organ reeds self-oscillate through repeated contact-with-shallot cycling. #expands (0.80)
• Reeds must vibrate faster than the air column to reinforce resonance #corroborates (0.75) — Eric J. Heller, Why You Hear What You Hear- An…, 1613