Considerations to take into account when making the equipment

If the size of the disc is increased, the amount of sound waves collected is also increased. Large parabolic dishes collect more sound. For instance, if the size is double, the amplification is the square of the difference in size. For example, a two-metre diameter dish will capture four times as much sound as a one-metre diameter dish.

For a clearer sound, the focal length is vital. The focal length represents the distance from the center of the dish to the focus point. With a longer focal length, the signal is less disrupted and more specific.

However there is one flaw in the designs of parabolic sound dishes. To focus a specific sound wave, the wave length of that wave has to be much smaller than the diameter of the dish itself. Because of this, most parabolic dishes have to sacrifice certain types of sounds to be more manageable in size.

Sound waves travel at 342 m/s through the air. In order to obtain an accurate sound (down to 20 Hz), one would require a parabola with a diameter of at least 17 meters (= 342 m/s / 20 Hz). 20Hz is the lowest sound in which human ears can detect.

Hence, in order to make a suitable parabolic microphone that can be adjusted easily according to the target, it cannot be too big. Most birds produce sounds with at least 500Hz to beyond 8000Hz. Hence, the ideal size for the microphone, such that it is easy to move around is around 34cm (342m/s/1000Hz)