Audio refers to audible sound – the sound perceivable by the human hearing system, or the sound of a frequency belonging to the audible frequency range (20–20,000 Hz). Audio can be generated from various sources and perceived as speech, music, voices, noise, or any combinations of these. The perception of an audible sound starts by the sound pressure waves hitting the eardrum of the outer ear. The generated vibrations are transmitted to the cochlea of the inner ear to produce mechanical displacements along the basilar membrane. These displacements are further transduced into electrical activity along the auditory nerve fibers, and finally “analyzed” and “understood” in the central auditory system [4, 7].
The step from the fundamental definition of audio towards the concept of audio signalcan be seen as a step towards the birth of the modern consumer electronics. An audio signal is a signal that contains audio information in the...
- 2.ISO/IEC 11172-3:1993. Information technology – coding of moving pictures and associated audio for digital storage media at up to about 1,5 Mbit/s – part 3: Audio; 1993.Google Scholar
- 3.ISO/IEC 13818-3:1998. Information technology – generic coding of moving pictures and associated audio information – part 3: Audio; 1998.Google Scholar
- 4.Pickles JO. An introduction to the physiology of hearing. London: Academic; 1988.Google Scholar