CPI EVP Classification & Analysis 3 — Questions and Answers
Question 1: What characteristic distinguishes a Class C EVP from Classes A and B?
- It is captured on video rather than audio
- It is extremely faint, heavily disputed, and often unintelligible even after processing (Correct answer)
- It contains music rather than speech
- It is only audible on analog tape recorders
Correct answer: It is extremely faint, heavily disputed, and often unintelligible even after processing
Class C EVPs are the lowest quality designation—so faint or distorted that listeners routinely disagree on content, making them weak evidence.
Question 2: An EVP analyst uses a spectrogram to review a recording. What axis typically represents time in a standard spectrogram display?
- Vertical (Y) axis
- Horizontal (X) axis (Correct answer)
- Color saturation axis
- Amplitude (Z) axis
Correct answer: Horizontal (X) axis
In a standard spectrogram, the horizontal X-axis represents time, the vertical Y-axis represents frequency, and color or brightness represents amplitude.
Question 3: During evidence review, an EVP appears to directly answer a question asked by an investigator two seconds earlier. This type of EVP is often categorized as which specialized subtype?
- Residual EVP
- Intelligent or interactive EVP (Correct answer)
- Imprinted EVP
- Ambient EVP
Correct answer: Intelligent or interactive EVP
An EVP that responds contextually to a question is classified as intelligent or interactive, suggesting real-time awareness rather than a residual loop.
Question 4: Which audio editing practice is considered unethical and inadmissible under standard paranormal investigation evidence protocols?
- Normalizing volume levels
- Applying a high-pass filter to remove low-frequency rumble
- Adding reverb or echo effects to enhance perceived voice quality (Correct answer)
- Exporting to WAV format
Correct answer: Adding reverb or echo effects to enhance perceived voice quality
Adding reverb, echo, or other creative effects to an EVP recording alters the evidence and constitutes manipulation, rendering it inadmissible.
Question 5: What is the recommended minimum sample rate for EVP capture to adequately represent the full range of human speech frequencies?
- 8,000 Hz (8 kHz)
- 22,050 Hz (22.05 kHz)
- 44,100 Hz (44.1 kHz) (Correct answer)
- 192,000 Hz (192 kHz)
Correct answer: 44,100 Hz (44.1 kHz)
44.1 kHz is the CD-quality standard that captures frequencies up to 22 kHz, well beyond the upper limit of human speech and hearing.
Question 6: A control recorder placed in a sealed, unoccupied room during an EVP session primarily serves what function?
- To capture spirit voices in isolation without investigator contamination
- To provide a baseline reference that helps identify building sounds and environmental noise (Correct answer)
- To test battery life under investigation conditions
- To document investigator movement patterns
Correct answer: To provide a baseline reference that helps identify building sounds and environmental noise
A control recorder in an isolated area captures ambient building sounds, HVAC noise, and other environmental factors that may otherwise be mistaken for EVP.
Question 7: Which phenomenon occurs when a radio or other broadcast signal is unintentionally captured by an EVP recorder, producing voice-like sounds that mimic paranormal communication?
- Transaudient leakage
- Radio frequency bleedthrough or RFI contamination (Correct answer)
- Subharmonic resonance
- Thermal acoustic coupling
Correct answer: Radio frequency bleedthrough or RFI contamination
RFI contamination occurs when a recorder's circuitry inadvertently acts as a radio receiver, capturing broadcast signals as false EVP.
CPI EVP Classification & Analysis 3
What characteristic distinguishes a Class C EVP from Classes A and B?