Audio & Video Evidence Review Flashcards

When reviewing IR (infrared) video footage, which artifact is most commonly mistaken for a paranormal anomaly?

Answer: Dust particles reflecting IR light (orbs)

Dust particles in close proximity to the IR illuminators reflect light and appear as bright floating orbs, the most common camera artifact misidentified as paranormal.

What is the primary purpose of using a digital voice recorder with a built-in noise-reduction feature during EVP sessions?

Answer: To reduce background hiss so faint anomalous voices are more audible

Noise reduction lowers the ambient hiss floor, making any anomalous sounds stand out more clearly against the background.

A Class B EVP is best described as:

Answer: A voice that is audible but requires some audio enhancement and may not be agreed upon by all listeners

Class B EVPs are audible without major processing but are not universally agreed upon; they occupy the middle tier of the EVP classification system.

Which video review technique helps investigators determine whether a moving anomaly is on the camera lens versus actually in the room?

Answer: Checking whether the anomaly moves in relation to fixed background objects

An anomaly on the lens will not move relative to the fixed background, whereas something genuinely in the room will shift position against background reference points.

What does 'gain staging' mean in the context of EVP audio review?

Answer: Setting each amplification stage so that signals are boosted without introducing clipping distortion

Gain staging is the process of managing volume levels at each step in the audio chain to maximize signal quality while preventing clipping or excessive noise.

During video review, a shadow anomaly is observed crossing a wall. Which control condition BEST rules out a natural explanation?

Answer: Checking simultaneous footage from a second camera covering the same area

A second synchronized camera provides an independent vantage point; if the shadow appears on one camera but not the other, it suggests a camera artifact rather than a real phenomenon.

What is 'apophenia' and why is it relevant to EVP analysis?

Answer: The tendency to hear meaningful patterns (such as words) in random noise

Apophenia is the human tendency to perceive meaningful patterns in random stimuli; in EVP analysis it can cause investigators to 'hear' words in white noise or static that are not actually present.

Which type of microphone pickup pattern is generally preferred for EVP sessions to minimize room reverb and focus on nearby sounds?

Answer: Cardioid

A cardioid microphone captures sound primarily from the front while rejecting much of the reverb and noise coming from the sides and rear, making it effective for focused EVP capture.

When timestamping video evidence, why is syncing all cameras to a single time reference critical?

Answer: It allows cross-referencing of anomalies across multiple cameras to confirm or debunk them

A shared time reference allows investigators to determine whether an anomaly captured on one camera corresponds to anything on other cameras at the exact same moment.

What is the 'stone tape theory' and how does it relate to audio/video evidence review?

Answer: A theory that building materials absorb and replay past events as sounds or images, used to contextualize unexplained audio/video anomalies

The stone tape theory proposes that materials like stone can record and later play back past events; investigators sometimes use this framework to contextualize audio or visual anomalies in old stone buildings.

A video shows a figure that disappears when the investigator enters the room but was clearly visible on the monitor. What is the most likely technical explanation?

Answer: Monitor display lag caused the investigator to see a delayed image that had already resolved

Display lag (latency) on monitors connected to live cameras can show an image that is several frames behind real time, making it appear as though something vanished upon the investigator's entry.

Which software feature is most useful for isolating a suspected EVP buried within constant low-frequency rumble?

Answer: A high-pass filter set to cut frequencies below the rumble threshold

A high-pass filter removes low-frequency rumble below a chosen cutoff point, allowing higher-frequency voice content to be heard more clearly.

What is 'matrixing' in the context of video evidence review?

Answer: The brain's tendency to find familiar shapes (like faces) in random visual patterns such as shadows or textures

Matrixing is the human brain's propensity to recognize familiar shapes, particularly faces, within random patterns; this can lead investigators to misidentify shadows or textures as apparitions.

Which practice BEST reduces contamination of audio evidence during a multi-investigator EVP session?

Answer: Using a call-and-response protocol where only one investigator speaks at a time and each statement is verbally tagged with the speaker's name

A structured call-and-response protocol with verbal speaker tags creates a clear audio record that allows reviewers to attribute every known voice, making unidentified voices stand out.

What does a 'full spectrum' camera capture that a standard consumer video camera does not?

Answer: Near-UV and near-IR light outside the visible spectrum, which some investigators believe may reveal anomalies

Full spectrum cameras have had their IR-blocking filter removed, allowing them to record near-ultraviolet and near-infrared light that standard cameras block, which some paranormal investigators believe may capture phenomena invisible to the naked eye.

An investigator notices a recurring audio anomaly at exactly 60 Hz. What is the most probable cause?

Answer: Electromagnetic interference from AC electrical wiring or equipment inducing a 60 Hz hum

60 Hz is the frequency of AC electrical current in the US; interference from wiring, power supplies, or unshielded cables commonly induces a 60 Hz hum into audio recordings.

Why is it important to document the temperature and humidity conditions during video evidence collection?

Answer: Condensation mist, fog breath, or thermal anomalies can create visual effects that are mistaken for apparitions

Breath condensation in cold air, water vapor, and temperature-related visual effects can appear on camera as mist or moving shapes that mimic apparitions, so environmental data allows reviewers to rule out these causes.

What is the recommended minimum sample rate for recording EVPs to ensure voice frequencies are accurately captured?

Answer: 44,100 Hz (44.1 kHz)

44,100 Hz (CD quality) satisfies the Nyquist theorem for capturing all frequencies within the human hearing range (up to ~20 kHz) without aliasing distortion, and is the standard recommended minimum for EVP work.

During evidence review, an investigator plays an EVP clip to ten colleagues; five hear a voice saying a word and five hear nothing. How should this EVP be classified?

Answer: Class C, because it lacks consensus and is barely discernible

A Class C EVP is very faint or unclear, with no consensus among listeners; a 50/50 split with some hearing nothing aligns with the Class C 'barely discernible and contested' description.

What technique involves playing white noise or pink noise during a recording session in hopes of providing a medium through which an EVP voice can manifest?

Answer: Instrumental Trans-Communication (ITC) using a noise source

Instrumental Trans-Communication (ITC) encompasses methods of using electronic devices—including white noise generators—as a purported medium for spirit communication, with any resulting voices captured on the recording.