This study aims to determine the length of the felxural tube phonocardiograph device for noise reduction from heart sound record data. Human. Phonocardiograph, which is a simplification of the phonocardiograph in the chest part (in whole) in the chest; pipe; condenser mic; pre-amp; PC. The data is then processed using the fast fourier transform (FFT) method to change the time domain to a domain that can be used with baseline data. Data processed by FFT PCG that uses a flexible tube as a filter are compared to those that use filters to influence the noise reduction. In terms of the length of the felxural tube there is a significant frequency obtained. The results of heart rate comparison through PCG with filters and without filters, then PCG with a flexible tube length of 1000 cm is the most optimal result in the FFT baseline.