Threshold of hearing in a young normal adult is ?

Ans. is'a'i.e.,0 dBAudiometric zeroThreshold of hearing, i.e. The faintest intensity which a normal healthy person can hear will vary from person to person.The International Standards Organisation (ISO) adopted a standard for this, which is represented as the zero level on the audiometer (0 dB).According to ISO, audiometric zero is the mean value of minimal audible intensity in a group of normally hearing healthy young adults.