FoundationalConceptsNeuroscience

seconds to negotiate each kilometer: about 15 seconds to travel 5 kilo-

meters. So there will be a 15-second gap between seeing the lightning

and hearing the associated thunder. One can estimate how far away

lightning is by counting the seconds between seeing the lightning and

hearing the thunder. If the gap is a second or less, take care.

[\ [\ [\ Compression

Air pressure Normal

VU VU VU Rarefaction

0 5 10 15

Time (milliseconds)

Figure 15.2. Sound shown as a sine wave.

Figure 15.3. Sine waves with lower (left) and higher (right) frequencies.

You may have had a similar experience in watching displays of
fireworks. Depending upon how far away you are from the exploding
firework, there may be a gap of a second or two, or even many seconds,
between seeing the exploding firework in the sky and hearing the as-
sociated boom.

Sensory channels are sensitive to limited ranges of stimuli. For light,