From "ThermoAcoustics and the Rijke Tube: Experiments, Identification, and Modeling", thermoacoustic instability can be subsided using an amplifier and a speaker.
It says in page 4,
The microphone signal (AC coupled) is fed via the DAQ board to Simulink, where it is recorded and multiplied with the variable gain.
Isn’t it merely increasing the amplitude of the audio input? How is it possible to reduce thermoacoustic combustion instability?