The pulse counter in the exchange counts the pulses or clicks and interprets them in two possible ways.
From the en.wikipedia.org
There's also a hustling counter-pulse, so the two rhythms sound as if they're racing each other.
From the guardian.co.uk
Jauregui grabbed a phone to call 911, jumped over the ticket counter to check his pulse.
From the us.cnn.com
The narrow peak associated with the counter-propagating pulse interaction is Doppler-free and has a width that is proportional to the pulse duration.
From the nature.com
First, we show that the addition of a counter-propagating pulse changes the quantum interference and can even invert the properties of the excitation.
From the nature.com
Each particle detected produces a pulse of current, but the Geiger counter cannot distinguish the energy of the source particles.
From the en.wikipedia.org
However, the combination of two such dark pulses with a nonzero delay is no longer dark and therefore permits excitation exclusively through the counter-propagating, Doppler-free pulse interaction.
From the nature.com
The relative timing between both counter-propagating pulses was adapted by timing each pulse relative to a transverse probe pulse, using plasma shadowgraphy techniques.