Which method related to IEDs involves using sound to trigger activation?

The method involving the use of sound to trigger activation of an Improvised Explosive Device (IED) is based on utilizing auditory cues or noise as a mechanism for detonation. This approach can exploit various sounds, such as a specific frequency or loud noise, to trigger the triggering mechanism within the IED.

Using sound as a means of activation allows for a diverse range of triggers based on environmental noise or intentional signals. This method can be advantageous, as it might allow for remote activation, ensuring the individual deploying the device can be at a safe distance.

Other methods, such as pressure activation or light detection, involve physical changes or environmental stimuli that would not be applicable for an auditory-based activation system. Similarly, magnetic triggering relies on magnetic fields and is distinct from sound-based mechanisms. Thus, choosing sound accurately reflects a recognized method in explosive device deployment that matches the parameters of the question.