Abstract

Background: Cardiac auscultation is a frequent first step in diagnosing heart disorders. However, the lack of dependability of ordinary auscultation in the hands of inexperienced clinicians remains a problem.

Objectives: We sought to develop an inexpensive system for digital cardiac auscultation (digital phonocardiography) using a Windows laptop computer, freely downloadable software and an inexpensive USB microphone.

Description: The system, based on the free open-source Audacity software package, offers advanced features such as phonocardiogram storage and retrieval, low-pass and high-pass waveform filtering and variable-speed signal playback with pitch preservation.

Results: Sample results for both raw and digitally filtered phonocardiograms are provided.

Conclusion: An innovative laptop-based phonocardiogram system offering advanced features can be easily produced at minimal cost.

Keywords: Audio signal processing, Audacity audio software package, Digital phonocardiography, Digital signal processing, Heart sounds, Phonocardiogram.