Sound distortion feedback

Abstract

A system is described for facilitating correct performance of CPR by providing feedback to a person performing chest compressions during basic life support or CPR training. The device is adapted to give audio signals to the user indicative of chest compressions being within a desired range or being outside of the desired range. In a first aspect the audio signal comprises two tones, a first tone that is substantially constant in pitch and a second tone that has a varying pitch. The pitch of the second tone is varying in response to a parameter of the chest compression performance. When the parameter is within a desired range, the second tone has substantially the same pitch as the first tone and when the parameter is outside the desired range, the pitch of the second tone is different from the first tone. In a second aspect the audio signal is a piece of music. This is played back at normal speed when a parameter of the chest compression performance is within a desired range and played back at a different speed when the parameter is outside off the desired range. In a third aspect the piece of music is played back with a normal range of frequencies when the parameter is within the desired range. If the parameter is outside the desired range the piece of music is played back using a cut off filter that reduces or eliminates certain frequency ranges of the piece of music.

Dependencies are inferred from the claim text.