Read the following case and answer the questions given below:
As part of a classroom demonstration, a group of students used a mobile application that could generate sounds of different frequencies. Their teacher asked them to investigate how changing the frequency affects the sound they hear.
The students first set the frequency of the sound generator to \(100\ Hz\) and played the sound. They listened carefully to the sound and then increased the frequency in steps of \(100\ Hz\), noting how the sound changed each time.
Next, they set the frequency to \(50\ Hz\) and gradually reduced it. As the frequency approached \(20\ Hz\), they noticed that the sound became increasingly difficult to hear. At a sufficiently low frequency, they could no longer hear the sound.
The teacher asked the students to relate their observations to the concept of pitch and the range of frequencies that can normally be heard by humans.
The students first set the frequency of the sound generator to \(100\ Hz\) and played the sound. They listened carefully to the sound and then increased the frequency in steps of \(100\ Hz\), noting how the sound changed each time.
Next, they set the frequency to \(50\ Hz\) and gradually reduced it. As the frequency approached \(20\ Hz\), they noticed that the sound became increasingly difficult to hear. At a sufficiently low frequency, they could no longer hear the sound.
The teacher asked the students to relate their observations to the concept of pitch and the range of frequencies that can normally be heard by humans.
1. When the students increased the frequency of the generated sound from \(100\ Hz\) in steps of \(100\ Hz\), which change would they primarily observe in the sound?
2. After completing the activity, a student concludes: “If I cannot hear a sound, then the sound has not been produced.” Which observation from the activity provides the strongest reason to reject this conclusion?