Action Potentials (Spikes)
The output of every neuron consists of a sequence of pulses known as action potentials or spikes. Every spike has the same waveform lasting about a millisecond (one-thousandth of a second).
Information about sound is carried in the timing of the spikes. For example, loudness is usually coded by neurons in how rapidly the spikes occur.
Recorded spikes from a neuron in the auditory pathway
Response of an auditory neuron to a tone turned on every 6 seconds.