What is Sound?

The symptom of sound is the sensation of hearing; thus it is a transmitted disturbance perceived or perceptible by the ear. But the ear is not merely a sensor for all auditory disturbances; what we listen also transmits certain qualitative meanings. Especially a tone, like that produced by regular vibrations and perceived as a harmony, as opposed to a set of differently produced noises. Mere noise in itself is meaningless. It is thus without sense or distinguished from sense. Sound thus is a stimulator of a mental impression; quality or level of noise; music; spoken commentary, music, sometimes accompanying visual material such as filmed or news footage.

Do our ears have hearing limits?
Depending upon the age and physical condition of a person, the ideal frequency range of hearing can be from 20 Hz to 20,000 Hz. The threshold of hearing varies drastically with frequency, whereas the threshold of feeling is at around SPL of 120 dB. Threshold of pain starts at 140 dB. Normal speech levels range from 40 to 75 dB.