Final answer:
Different perceptions or opinions of the same sound can be caused by a variety of factors such as cultural background, ear sensitivity, psychological factors, and the timbre of the sound, in addition to the frequency which affects pitch.
Step-by-step explanation:
The perception of sound can vary from person to person due to several factors. While sound frequency primarily determines pitch, and most individuals have good relative pitch, allowing them to discern if one sound is of a different frequency than another, the answer to what causes two people to have a different perception or opinion of the same sound includes more than just frequency. Factors such as cultural background, ear sensitivity, psychological factors, and the unique timbre of the sound produced by different instruments can all influence how a sound is perceived. For example, people can often tell that 500.0 Hz and 501.5 Hz are different sounds because they differ by more than 0.3%, yet other factors may still lead to different subjective experiences of these sounds.