How is it possible to detect the filling of a bottle under a water tap by hearing the sound at a distance?

Two identical guitars are played by two persons to give notes of the same loudness and pitch. Will they differ in quality? Give a reason for your answer.

How does the wave pattern of a loud note differ from the soft note? Draw a diagram.

Draw a diagram to show the wave pattern of high pitch note and a low pitch note, but of the same loudness.