Final answer:
The quality, richness, fullness, and loudness of the voice are chiefly produced by timbre, which involves the frequency, amplitude, and timing of sound waves. Timbre enables us to distinguish different sounds and is also key in discerning the emotional nuances in music or speech.
Step-by-step explanation:
What is perceived as quality, richness, fullness, and loudness of the voice is largely produced by a combination of factors including frequency, amplitude, and timing of the sound wave. This perception is commonly referred to as timbre.
Timbre, or tone quality, helps us distinguish different types of sounds, such as the difference between a violin and a piano playing the same note. While the loudness of a sound is related to its intensity, frequency also significantly affects our perception of loudness, with the ear being less sensitive at extreme high and low frequencies.
Human speech is produced by air being pushed through the lungs, passing through the vocal cords which vibrate, and then shaped by the throat and mouth. The manipulation of these elements affects the fundamental frequency and the harmonics involved, contributing to the timbre of the human voice.
Instruments and voices have distinctive sets of frequencies and intensities which are processed by the hearing mechanism and translated into neural signals interpreted by the brain. These characteristics are not merely physical but also engage higher-level processes within our perceptual psychology, influencing the way we perceive the richness and emotion in someone's voice or in music.