PHYSIOLOGICAL CHEST SOUNDS AND HELICOPTER ENGINE NOISE

To develop an amplification system for physiologic chest sounds during dir medical transport In jet helicopters, we compared frequency spect ra of physiologic chest sounds and Allison C-28 equipped jet helicopte r noise. We found that the frequency spectrum of physiologic chest sou nds is contained entirely within that of jet rotorcraft noise. Attempt s to amplify physiologic chest sounds or to filter jet rotorcraft nois e will invariably fail to improve perception of chest sounds. Future r esearch must focus on assessment of actual movement of the chest and o f each hemithorax, as well as on carbon dioxide production, as Indicat ors of adequate ventilation and proper endotracheal tube position.