An audiophile, from Latin audio "I hear" and Greek philos "loving," is a person, who typically listens to music on high-end audio electronics. Audiophiles try to listen to music at a quality level that is as close to the original performance as possible.
High fidelity or hi-fi reproduction is a term used by home stereo listeners and home audio enthusiasts (audiophiles) to refer to high-quality reproduction of sound or images that are very faithful to the original performance. Ideally, high-fidelity equipment has minimal amounts of noise and distortion and an accurate frequency response. By the 1990s, the term hi-fi for expensive high-quality home-audio electronics was largely replaced with high-end audio.
Sound is a vibration transmitted through a solid, liquid, or gas. Sound waves are characterized by the generic properties of waves, which are frequency, wavelength, period, amplitude, intensity, speed, and direction.
For humans, hearing is limited to frequencies between about 20 Hz and 20,000 Hz, with the upper limit generally decreasing with age. Most people living in developing countries cannot hear over 18 kHz till they have reached teenage. Half of the people over 35 cannot hear over 15 kHz. Most of the human speech takes place between 200-8000 Hz and the human ear is most sensitive to 1000 - 3500 Hz in the frequency range.
A loudspeaker, speaker, or speaker system is an electro acoustical transducer that converts an electrical signal to sound. A speaker will transform the electrical signal representing speech or music into vibrations of the membrane. The resonance of the membrane will produce acoustical energy which is translated by our ears as sound.