CPI Audio & Video Evidence Review 3 — Questions and Answers
Question 1: Which audio file format preserves the highest fidelity for EVP evidence and is recommended for archiving?
- MP3 at 128 kbps
- WAV (PCM uncompressed) (Correct answer)
- AAC at 256 kbps
- OGG Vorbis
Correct answer: WAV (PCM uncompressed)
WAV (PCM) is an uncompressed format that retains all original audio data without the lossy artifacts introduced by formats like MP3 or AAC.
Question 2: When an investigator reviews video and notices a bright streak moving across the frame, what is the most likely mundane explanation before attributing it to the paranormal?
- A spirit manifestation captured by the IR sensor
- An insect flying close to the camera lens and reflecting IR light (Correct answer)
- Electromagnetic interference from nearby power lines
- Compression artifacts caused by low storage bandwidth
Correct answer: An insect flying close to the camera lens and reflecting IR light
Insects flying near the camera lens are a very common source of bright moving streaks on IR night-vision footage and should always be ruled out first.
Question 3: What is 'spectral analysis' used for in paranormal audio evidence review?
- Visualizing the frequency content of a recording to identify anomalies not audible to the ear alone (Correct answer)
- Measuring the electromagnetic spectrum in a room during recording
- Converting audio EVPs into a visual light spectrum for comparison
- Determining whether a recording was made by a professional-grade microphone
Correct answer: Visualizing the frequency content of a recording to identify anomalies not audible to the ear alone
A spectrogram (spectral analysis) displays frequency versus time, allowing reviewers to spot voice-shaped patterns or anomalous sounds that may be outside normal hearing range.
Question 4: Which phenomenon causes digital video to show brief rectangular blocks or frozen frames, and could be misinterpreted as a paranormal event?
- Chromatic aberration
- Codec compression artifacts (macroblocking) (Correct answer)
- Rolling shutter distortion
- IR wash-out
Correct answer: Codec compression artifacts (macroblocking)
Macroblocking occurs when a digital video codec lacks sufficient data to encode a scene, producing pixelated rectangular blocks that can resemble apparitions if the reviewer is unfamiliar with the artifact.
Question 5: Why should investigators avoid whispering during an EVP recording session?
- Whispering damages condenser microphone diaphragms
- Whispers can be picked up at low volume and later misidentified as EVP responses (Correct answer)
- Whispering creates electromagnetic interference with digital recorders
- Audio software cannot distinguish whispers from background noise
Correct answer: Whispers can be picked up at low volume and later misidentified as EVP responses
Whispered voices from investigators can be captured by sensitive recorders and later mistaken for disembodied EVP responses during review.
Question 6: A 'control recording' made outside the active investigation area is used primarily to:
- Capture EVPs from uninvestigated rooms simultaneously
- Establish a baseline of environmental sounds to distinguish from anomalous audio (Correct answer)
- Test the recorder's battery life before a long session
- Document the investigator's spoken notes and timestamps
Correct answer: Establish a baseline of environmental sounds to distinguish from anomalous audio
A control recording made in a neutral location captures the ambient sound profile of typical environmental conditions, allowing reviewers to identify what is 'normal' versus anomalous.
Question 7: What standard practice ensures that a video anomaly is not dismissed as a simple camera malfunction?
- Formatting the SD card and re-recording at the same location
- Testing the camera in the same environment under the same conditions at a later date to attempt to replicate the effect (Correct answer)
- Upgrading the camera firmware before re-review
- Slowing the footage to 50% speed in post-production
Correct answer: Testing the camera in the same environment under the same conditions at a later date to attempt to replicate the effect
Replication testing involves returning to the location with the same equipment under similar conditions; if the effect cannot be reproduced, it remains unexplained rather than being attributable to a known malfunction.
CPI Audio & Video Evidence Review 3
Which audio file format preserves the highest fidelity for EVP evidence and is recommended for archiving?