Final answer:
The correct answer is that two sounds need to be separated by as little as 10 microseconds for the sound to be perceived as coming from the leading ear. This short time difference is important for sound localization and shows the complexities of human hearing that involve pitch and loudness discrimination. The option (B) is correct.
Step-by-step explanation:
Studies with humans have demonstrated that if two sounds presented through earphones are separated by as little as 10 microseconds, the sound will be perceived as being on the side of the leading ear. This small time difference allows the human auditory system to localize sound sources based on the timing of the sounds reaching each ear, a phenomenon known as sound localization.
The ability to discern directional sound is essential in everyday life, as it helps individuals identify where sounds are coming from in their environment. This spatial hearing, coupled with the ear's sensitivity to frequency and intensity differences, plays a vital role in the human auditory experience.
Hearing is an intricate sense that also involves discerning different frequencies, which is related to the perception of pitch. Humans typically can discriminate between two sounds if their frequencies differ by about 0.3% or 100 Hz. This capability extends to our perception of loudness as well, which is related to the intensity of the sound and can be distinguished in differences of about 1 dB. Therefore, option (B) is correct.