The invention relates to the field of 
noise control and utilization, particularly to a 
noise-reducing electrotransformation device for a central air-conditioning air supply 
pipe. The 
noise-reducing electrotransformation device for the central air-conditioning air supply 
pipe provided by the invention comprises a noise absorption unit, an 
audio frequency tracking unit and an acoustoelectric 
transformation unit, wherein the noise absorption unit is connected with the 
audio frequency tracking unit; the acoustoelectric 
transformation unit is arranged in the 
audio frequency tracking unit, and is externally connected with a 
voltage output circuit; and the audio frequency tracking unit is arranged on the outer wall of the central air-conditioning air supply 
pipe. The noise-reducing electrotransformation device has the advantages that by the 
resonance characteristics of a 
helmholtz resonator, 
noise energy of an air pipe is transformed into 
electric energy through piezoelectric ceramics, so that the noise of the air-conditioning air pipe is reduced; the 
electric energy is also generated; and in addition, the spectrum width of available noise can be increased by the audio frequency tracking unit.