These crackles and bronchial breathing were
recorded posteriorly over the consolidated left lower lung of a 16 year old boy
provides a visual representation of the content of the respiratory sound
recording. Time is shown on the horizontal and frequency on the vertical axis.
Sound intensity is indicated on a color scale, ranging from red (loud) over
yellow and light green (medium) to dark green and gray (low). Calibrated air
flow is displayed at the top (I = inspiration, above zero; E = expiration, below zero).