This is a fluidic amplifier from this patent.

It should have a pretty nice frequency response as it is intended to be used a part of a sound amplifier circuit for a gramophone.

If you make several other amplifiers according to the sizes in the patent and wire them up according to the patent, you sould be able to make a completely fluidic acoustic amplifier.

Specifications derived from patent:
Nozzle size is 0.02" x 0.016" and operating supply pressure is 0.5 PSI.

NOTE: this thing is tiny!