THE SENTINEL™

A Quieter Approach to Spirit Communication

The Sentinel™ represents a different approach to spirit communication equipment from Horn Paranormal Research.

Unlike a traditional spirit box, The Sentinel does not fill the room with a constant stream of radio sweep noise, static, or fragmented broadcasts.

Instead, its multi-band radio system continuously scans and analyzes multiple portions of the radio spectrum silently in the background.

The investigator asks questions, observes the environment and waits.

When The Sentinel generates a response, that response is spoken through the device and simultaneously displayed on its screen. Responses can be produced using male, female or child voice outputs, with support for both English and Spanish responses.

No constant sweep noise. No talking over the radio. No trying to determine whether a voice was simply part of a passing broadcast.

Ask your question.

Wait.

Listen for the response.

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5 BANDS • 3 SWEEP MODES • 2 LANGUAGES • 3 VOICE TYPES

The Sentinel combines a wide multi-band scanning system with multiple scanning behaviors and a diverse spoken response system—all within one self-contained instrument.

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THE SENTINEL LISTENS WHERE HUMAN EARS CANNOT

BEYOND THE RANGE OF HUMAN HEARING

Human ears and The Sentinel are listening to two very different things.

Human hearing detects acoustic sound—pressure waves traveling through the air. The commonly cited range of human hearing is approximately 20 Hz to 20,000 Hz (20 kHz) under ideal conditions, with the upper limit typically decreasing with age.

The Sentinel is doing something fundamentally different.

Its software-defined radio (SDR) is not simply listening for acoustic sounds that are too quiet for us to hear. Instead, it electronically monitors radio-frequency electromagnetic activity, measured in megahertz (MHz), across five different radio bands.

The Sentinel monitors frequencies ranging from 87.5 MHz through 470 MHz within its individual scanning bands.

Those radio frequencies are not sounds that the human ear can hear.

They are electromagnetic signals that require electronic equipment to receive and process.

This is an important distinction. The Sentinel isn't simply amplifying something that was too faint for you to hear. Its SDR receiver allows the system to monitor and process activity within portions of the electromagnetic spectrum that our ears cannot directly perceive at all.

And because The Sentinel performs this scanning and processing silently, the investigator doesn't hear the underlying radio sweep.

You hear the responses—not the sweep occurring behind them.

HUMAN EAR: Detects acoustic pressure waves, approximately 20 Hz–20 kHz under ideal conditions.

THE SENTINEL: Electronically monitors RF electromagnetic activity across five radio bands ranging from 87.5–470 MHz.

These aren't simply different frequencies of the same type of sound. Acoustic sound and radio-frequency electromagnetic energy are fundamentally different physical phenomena.

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MULTI-BAND RADIO SCANNING

The Sentinel isn't limited to the traditional FM sweep found in many spirit boxes.

Its internal SDR-based radio system scans across five different radio ranges, dramatically expanding the spectrum available to the system:

The Sentinel continually moves through these ranges rather than stopping and holding on individual stations or frequencies.

And unlike a conventional spirit box, you don't hear this scanning process.

The scanning, signal analysis and processing happen behind the scenes, allowing the investigation environment to remain quiet between responses.

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THREE SWEEP MODES

The Sentinel provides three distinct sweep modes, allowing investigators to change how the system moves through its active frequency ranges while maintaining the quiet operation that defines The Sentinel.

FORWARD — Progresses upward through the frequency range in sequence before continuing the scanning cycle.

REVERSE — Reverses the direction of the sweep, progressing downward through the frequency range.

RANDOM — Breaks away from sequential scanning and moves through frequencies in a randomized pattern, creating a less predictable method of sampling the spectrum.

Regardless of the selected mode, The Sentinel does not stop and hold on individual frequencies or stations. Scanning remains continuous and occurs silently in the background.

Combined with adjustable Sweep Speed and Gate, the three modes give investigators the ability to experiment with different scanning behaviors from one session to another.

Five radio bands. Three sweep modes. One quiet investigation environment.

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THE SILENCE IS PART OF THE EXPERIENCE

Traditional spirit boxes rely on an audible sweep. That means investigators often spend a session listening through rapid fragments of music, voices, static and broadcast material while attempting to identify possible responses.

The Sentinel was designed around a different idea:

What if you didn't have to listen through all of that noise?

With The Sentinel, the room can remain quiet.

Ask a question and give the system time to work.

When a response occurs, everyone present can hear it without having to separate it from a continuous radio sweep.

That creates a very different style of investigation—and makes periods of silence just as much a part of the session as the responses themselves.

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MALE, FEMALE & CHILD VOICE OUTPUTS

The Sentinel isn't limited to a single voice.

Its spoken response system can produce responses using male, female and child voice outputs, providing noticeably different audible characteristics during an investigation.

These are output voices—not a library of pre-recorded or canned responses. There is NO WORD BANK on the Sentinel

The Sentinel listens to and processes the activity it receives and produces its spoken output accordingly. The male, female and child voices provide different ways for that resulting output to be spoken rather than supplying a collection of predetermined phrases.

This allows the audible character of a session to change as responses occur.

Changes or patterns involving a particular voice type can then be compared with questions being asked, the location being investigated, other equipment activity and recorded evidence.

And because the underlying radio scanning remains silent, these voices aren't competing against continuous radio chatter.

When The Sentinel responds, you hear the response.

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ENGLISH & SPANISH RESPONSE CAPABILITY

The Sentinel incorporates English and Spanish language output capability.

Like its male, female and child voices, these language capabilities are not a collection of canned English or Spanish responses.

The Sentinel's output can be spoken in English or Spanish based on what the system receives and processes, rather than requiring the investigator to select a separate Spanish-only operating mode.

This adds another observable element to an investigation, particularly at locations where Spanish language, culture or history may be relevant.

Together, The Sentinel's male, female and child voice outputs and English/Spanish language capability provide multiple ways for its resulting responses to be presented to the investigator.

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ADJUST THE EXPERIENCE

Different locations create different radio environments, which is why The Sentinel gives the investigator control over several important operating parameters.

Sweep Speed — 100–250 ms
Controls how quickly The Sentinel moves through its scanning process.

Gate — 1–10
Controls how aggressively weaker signal activity is filtered. Lower settings allow weaker activity through, while higher settings require stronger activity.

Echo / Reverb
Adjusts the character and atmosphere of the spoken audio.

Volume
Controls the output level of The Sentinel's internal audio system.

These controls allow investigators to experiment with different configurations rather than being locked into a single operating profile.

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SEE, HEAR & REVIEW THE RESPONSE

When The Sentinel produces a response, you don't have to rely solely on what you thought you heard.

Responses are spoken through The Sentinel's internal audio system and simultaneously displayed on the touchscreen.

The system also maintains a session log, allowing responses to be reviewed during or after an investigation.

This makes it possible to compare responses with questions asked during the session, environmental events, other paranormal equipment, audio and video recordings, and responses occurring at different points during an investigation.

The goal isn't simply to hear something.

It's to give the investigator something that can be observed, documented and reviewed.

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PURPOSE-BUILT BY HORN PARANORMAL RESEARCH

The Sentinel isn't a commercially available radio placed inside a custom enclosure.

The hardware platform, scanning system, software, user interface, controls, audio system and enclosure were developed together to create a dedicated paranormal research instrument.

Each Sentinel combines its internal computer, SDR radio hardware, physical controls, speaker system, rechargeable power system, active cooling and external antenna connection into one self-contained portable device.

The result is equipment designed specifically around the way we wanted it to operate in the field—not around the limitations of an existing consumer radio.

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AN EXPERIMENTAL RESEARCH PLATFORM

Paranormal research is inherently experimental.

The Sentinel does not claim to prove the existence of spirits, nor can it guarantee that a response originates from a paranormal source.

Instead, it provides investigators with a platform for experimentation, observation and documentation.

Ask questions. Document the responses. Compare them with other equipment and recorded evidence. Look for repetition, relevance and patterns.

And ultimately, evaluate the results for yourself.

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THE SENTINEL™

LISTEN. DETECT. EXPLORE BEYOND.

5 BANDS • 3 SWEEP MODES • 2 LANGUAGES • 3 VOICE TYPES

Release Date: September 25th

Designed & Built by Horn Paranormal Research

15k MAH rechargeable battery. Approx. 3.5-4 hours continuous runtime

Approximate Size: 10" × 7" × 8"  

Weighs 2.5 lbs

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