Final answer:
The connection between sound frequency and nerve firing timing is known as the temporal theory of pitch perception, which applies to sounds below 1000 Hz.
Step-by-step explanation:
The connection between the frequency of sound stimulus and the timing of the auditory nerve fibers firing is called the temporal theory of pitch perception. This theory suggests that for sounds below about 1000 Hz, the nerves send signals at the same frequency as the sound. However, for frequencies greater than about 1000 Hz, the nerves indicate frequency by position rather than by the rate of firing. The brain processes these signals to identify the sound, which can include nuances such as music appreciation, thanks to the intricate operation of the cochlea and auditory nerve fibers.