Three audio technicians, A, B, and C, are testing sound equipment at an outdoor music festival.
Technician A is initially at a distance of 15.0 m15.0\text{ m}15.0 m from a loudspeaker, where the sound intensity is measured to be 8.0×10−8 W m−28.0 \times 10^{-8}\text{ W m}^{-2}8.0×10−8 W m−2. Technician A then moves to a distance of 25.0 m25.0\text{ m}25.0 m from the loudspeaker. Calculate the sound intensity at this new position. Assume that the loudspeaker behaves as a point source.
The sound intensity level is 83 dB83\text{ dB}83 dB at the position of technician B and 58 dB58\text{ dB}58 dB at the position of technician C. Calculate the ratio sound intensity at the position of Bsound intensity at the position of C\frac{\text{sound intensity at the position of B}}{\text{sound intensity at the position of C}}sound intensity at the position of Csound intensity at the position of B.
Technician B perceives the loudness of the sound differently than technician C. Discuss whether the use of intensity level or intensity is more appropriate to compare their perceived loudness.
All three technicians then move to a control cabin, positioning themselves at the same distance from a reference speaker playing music.
Describe how the perceptions of the music by A and B differ from that of C.
14 exam-style questions on AQA A Level Physics Physics of the ear (A-level only), covering Ear as a sound detection system (A-level only), Sensitivity and frequency response (A-level only), and Defects of hearing (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.