System Codex

A musical disorder that appears mainly as a defect in processing pitch, but also encompasses musical memory and recognition. Often called 'Tone Deafness'.

A logarithmic unit of measure for musical intervals. There are 100 cents in a semitone.

The most common form of color blindness, caused by missing green photoreceptors. Green is often confused with red.

A mathematical algorithm used by this test to convert the microphone's audio signal from time domain to frequency domain to detect pitch.

The lowest frequency of a periodic waveform, perceived as the pitch of the voice.

The unit of frequency in the International System of Units (SI), equal to one cycle per second. Humans typically hear between 20 Hz and 20,000 Hz.

A color perception test for red-green color deficiencies, consisting of pseudoisochromatic plates.

The minimum difference in stimulation that a person can detect 50% of the time. In this test, it is the smallest Hz difference between two tones.

The process of coating the axon of each neuron with a fatty coating called myelin, which protects the neuron and helps it conduct signals more efficiently.

The cumulative effect of aging on hearing, characterized by the progressive loss of high-frequency sensitivity due to hair cell degradation in the cochlea.

A type of color blindness characterized by the absence of red retinal photoreceptors. Red appears dark.

The time required for an observer to detect the presence of a stimulus.

Microscopic hair-like projections on the hair cells within the inner ear that transform mechanical sound vibrations into electrical nerve impulses.

The most comfortable vocal range for a singer, where the voice has the best timbre and is easiest to produce.