INVISIO AHP: Tactical Communication Without Compromising Hearing in High-Intensity Operations

The problem nobody names: the operator who can't hear

Hearing is the soldier's primary alert sense. The eye requires orienting the head; the ear covers 360°. The detection of footsteps, voices, the metallic click of a safety, the close pass of a projectile — all that information reaches the brain before the operator can look toward the danger. When that capability is damaged, survival probability drops.

The modern operations environment destroys hearing with systematic efficiency. An M4 rifle shot at 1 meter generates 160 dB — enough to cause permanent irreversible damage in a single exposure. A flash-bang grenade in a closed space exceeds 180 dB. The Mi-171 rotors, the tactical insertion aircraft of most Peruvian special operations units, produce 95-105 dB continuous with 130 dB peaks during landing. Operators without hearing protection lose hearing capacity irreversibly after weeks of operations.

The historic dilemma was: hearing protection or communication. Standard earplugs attenuated 25-30 dB but also blocked the critical voice frequencies. Operators had to choose between hearing the radio or protecting their hearing. In combat environments, most chose to hear the radio — and paid the price in cumulative hearing loss.

INVISIO resolved this dilemma more than 15 years ago. Their systems are in active service with special forces of 50+ NATO countries.

The AHR architecture: Active Hearing and Radio

INVISIO's Active Hearing and Radio (AHR) is not simply hearing protection with an integrated radio. It is an acoustic signal processing architecture that distinguishes in real time between signals the operator needs to hear and signals that can cause damage.

<1 ms threshold detection: The system continuously monitors ambient sound pressure level. When it detects an acoustic event above 85 dB — the hearing damage threshold for prolonged exposure — it activates attenuation in less than 1 millisecond. The operator hears the environment at safe volume but the damaging impulse (the shot, explosion, metallic impact) does not reach the auditory system.

Weak signal amplification: At the other end, AHR actively amplifies acoustic environmental signals below normal voice threshold — footsteps on soft ground, weapon mechanism clicks, whispers. The operator with INVISIO hears their environment with greater sensitivity than without protection, simultaneously protected against damage.

Bone conduction: The INVISIO V20 and V60 in-ear headsets transmit the radio signal by bone conduction through the ear cartilage, leaving the ear canal free for environmental perception. Unlike a conventional headset that occupies the ear, the INVISIO in-ear allows simultaneous radio and environmental hearing without signal conflict.

Dual-radio integration: X5 and Q7

The X5 control unit is the system core for high-demand operations. It simultaneously connects two independent radios — any combination of P25, TETRA, DMR, VHF/UHF analog — with independent per-ear audio mixing.

The operator can assign Radio 1 (e.g., Motorola MOTOTRBO XPR7580, the platoon base network) to the right ear and Radio 2 (e.g., Harris Falcon III or TrellisWare TSM on a covert net) to the left ear. Each channel's volume adjusts independently. When simultaneous traffic arrives on both channels, the system applies automatic "ducking" — reduces the secondary channel volume while the primary has activity and restores it when it stops.

This capability is critical for operators who need to simultaneously maintain the platoon tactical frequency (near command) and the fire support or air element coordination frequency (higher command). With conventional equipment, that operator carries two radios with two different headsets, manages two PTTs, and pays the cognitive penalty of processing two conflicting audio channels.

Applications in the Peruvian theater

Mi-171 insertion — VRAEM: The system amplifies team cabin voices while attenuating rotor noise. Briefing, last-minute adjustments, and confirmations are audible normally. On landing (130 dB peaks), AHR activates maximum attenuation in <1 ms. The operator exits the helicopter with intact hearing capability.

Urban breaching: The M2 with ballistic cups is compatible with the Galvion Batlskin Caiman. The operator enters the room with active microphone that lets them hear interior movement. The flash-bang activates AHR. On recovering position, the operator is in active radio communication with the exterior support element.

Low jungle — radio difficulties: Without INVISIO, operators increase radio volume to maximum, revealing position by speaker sound in the jungle silence. With INVISIO, radio audio goes directly to the in-ear — no external acoustic emission, no position-revealing risk.

EMAR SYSTEMS manages the EAR/ITAR export documentation process for Peruvian Armed Forces and PNP acquisitions, with current SUCAMEC clearance for dual-use equipment.