American Diagnostic Corporation (ADC) 657 Electronic Stethoscope - Manual (Page 5)

2.
Features
Main features of the ADC ® 657 electronic stethoscope
• Improves low frequency sound transmission characteristics with the use of a piezopolymer
film contact microphone.
• MPU controlled automatic power-off.
• Mode selection (Bell, Diaphragm, Wide).
• 8-level digital volume control.
• Memorizes the mode and volume of the previous operation.
• Ergonomic design for comfort.
An acoustic microphone used in most electronic stethoscopes may have frequency charac-
teristics not suitable for body sounds, especially for the low frequency heart sounds. Other stetho-
scopes provide the internal body sounds not directly from the body surface, but through the air layer
between the body surface and the microphone.
The ADC ® 657 solves those problems with the use of its piezopolymer
film contact microphone, which is at the heart of the ADC ® 657.
The ADC ® 657 has wide frequency characteristics, enabling you to
detect the heart and lung sounds more precisely.