The Littmann Electronic Stethoscope Model 4100 features amplification and proprietary Ambient Noise Reduction (ANR) technology allowing reduction of ambient noise without elimination of critical body sounds. It offers recording (storage and playback) capabilities and the ability to transfer recorded sounds via an infrared transmission. Comes with software allowing a phonocardiogram visual display.
The advanced technology of the Littmann Electronic Stethoscope Model 3000 features amplification and proprietary Ambient Noise Reduction (ANR) technology, allowing you to reduce ambient noise by an average of 75% (-12dB) without filtering out critical body sounds.