Permanent magnet is not used in compasses.

Explanation:
- A compass is an instrument used for navigation and orientation that shows direction relative to the geographic cardinal directions (or points).
- It consists of a magnetized pointer (usually a magnetic needle) that aligns itself with the Earth's magnetic field, which is generated by the movement of molten iron in the Earth's outer core.
- The magnetized pointer in a compass is not a permanent magnet. Instead, it is a small magnet that is magnetized by the Earth's magnetic field.
- When the compass is held horizontally, the magnetized pointer aligns itself with the Earth's magnetic field and points towards the Earth's magnetic North Pole.
- This allows the user to determine the direction they are facing and navigate using the compass.
- Since the magnetized pointer in a compass is not a permanent magnet, it does not rely on the properties of a permanent magnet to function.
- Instead, it relies on the Earth's magnetic field to magnetize the pointer temporarily and show the direction.
- The other options mentioned, such as magnetic door catchers and loudspeakers, do use permanent magnets.
- Magnetic door catchers use a permanent magnet to attract and hold the door in a closed position.
- Loudspeakers use a permanent magnet and an electric current to convert electrical signals into sound waves.
- Therefore, the correct answer is option 'D' - None of these, as compasses do not use permanent magnets.