instrument for hearing the pulse
• (n.) An electrical instrument for determining by the ear the rhythm of the pulse of a person at a distance.
Sphyg'mo·phone noun [ Greek ......... the pulse + ......... sound.] (Physiol.) An electrical instrument for determining by the ear the rhythm of the pulse of a person at a distance. 
Type: Term Pronunciation: sfig′mō-fōn Definitions: 1. An instrument by which a sound is produced with each beat of the pulse.
sphygmophone An instrument by which pulsations are rendered audible.