Former theories of the production of edge tones are reviewed and a new theory is put forward which accounts in a qualitative manner for the phenomena described in the preceding paper. The effect of the wake of a disturbance on the portion of the jet immediately following it is considered, and it is concluded that the compressibility and structure of the surrounding medium must be taken into account, and that, for low velocities, wake disturbance is the controlling factor, whilst for higher velocities the effect of the sound emitted must be taken into account. An attempt is made also to account for the differential sensitivity to frequency found in sensitive jets in a former research.

The production of edge tones in jets is influenced by compressibility and structure of the surrounding medium, with wake disturbance being the controlling factor for low velocities and sound emission for higher velocities.

The mechanism of edge-tone production

Key Takeaway: The production of edge tones in jets is influenced by compressibility and structure of the surrounding medium, with wake disturbance being the controlling factor for low velocities and sound emission for higher velocities.