Targeting

One of the audio anomalies we have encountered are the many examples of targeting. To gain a better understanding of what is actually happening I tested Olympus 600/700 audio recorders with and without external Sony ECM-DS70P Electret Condenser microphones, showing the anomaly can target its acoustical voice, shown above in the spectrogram. The reason for using external microphones is to reduce noise contamination through the embedded microphones in the body of the recorder. 

Condenser microphones consist of a capacitor with one plate fixed and the other forming the diaphragm moved by sound waves. The inductance of the capacitor’s wire leads is susceptible to RF interference. Although not as much as the dynamic microphone which is far more sensitive to RF contamination. We also tested the fake Sony ECM-DS70P and found them to have a better high frequency response.

When laying out voice recorders in circles, end to end, side to side, directly in front of the researchers. Using both dynamic, and condenser microphones we found the anomaly could target its response. In one experiment when we looked at the audio from the Zoom 360 4-channel microphones it showed a linear path across the room to the researchers’ recorder. We position team members around a table with their recorders directly in front of them showing targeted responses.

Another explanation of targeting described to me by using sound reflection. That sound waves bounce around the room reflecting off the surfaces in the room. Different surfaces absorb frequencies differently, so that some audio recorders would record the sound while others would not depending on location, and the materials nearest the audio device. The sound engineer’s explanation is valid for frequencies of 30dB and higher, but has not taken into account the amplitude of frequencies below -44dB there is a cost of absorption loss when reflecting sound waves at low amplitude would quickly reduce the frequency to zero, supporting a line of sight, other than reflection.

Having an explanation does not necessarily mean there is an absolute conclusion.

A simpler explanation to explain the targeting results for stereo microphones would be a channel failure along with sound reflection if it were not for multiple incidences using different audio recorders. I guess if the answer were easy, we would not call it an anomaly.

The difference between an electronic voice phenomena and a disembodied voice is the amplitude of the sound wave.

There is a frequency threshold between electromagnetic voice phenomena and acoustical voice phenomenon. Which would also explain the results between the dynamic or condenser microphone it’s not so much as being vulnerable to EM frequencies as to which is better at picking up faint low-frequency sound.