Low-Profile Voice Communication System

Ideal for High-Security Locations

The TTU-4 Talk Thru communication system is particularly suitable for low ambient noise environments that require an unobtrusive, yet tamper-resistant voice communication system.

The TTU-4's counter-mounted design eliminates the need for cutting into a barrier. Its low-profile installation adds a personal dimension to such situations as inmate-to-visitor communications.

All the components including the microphones are housed in the sleek, compact units to avoid the hazards that might be encountered in a high-security environment.

The TTU-4 incorporates the same high-quality electronics as the basic Patent Pending (#4049911) Norcon TTU-1 Talk Thru system. It is a Vox System, enabling the inmate and the visitor to have hands free two-way communication.

The Norcon TTU-4 provides clear communication, shaping the sound for maximum intelligibility. Its compression circuitry decreases loud, annoying sounds. Since the TTU-4 is designed for applications in security areas, all controls and microphones are recessed to minimize unauthorized adjustment and tampering. All exposed hardware is temper-resistant.

The TTU-4 comes ready to operate. The prism units are quickly and easily mounted on the counter-top on opposite sides of the barrier. They can be positioned back-to-back (as shown) or randomly. The unit with the controls goes on the visitor side of the barrier. Tamper resistant screws are used for both units. A special tool is furnished for these screws. There are two-ways to install the TTU-4: either run the cable between the units through a small hole in the barrier, or under the counter-top.

The TTU-4 uses a continuous-duty, 117-Volt power supply which is stepped down to 15 Volts.

To order please call 802-824-9808 or send and email to .(JavaScript must be enabled to view this email address).


TTU-4™ Diagrams TTU-4™ Diagrams



  • Clear 2-way hands-free voice communication.
  • Quality electronic design and engineering.
  • Avoids shouting, repetition, misunderstanding.
  • No gooseneck microphone and no external controls.
  • Rugged, tamper-resistant materials.
  • Simple, one-person installation.
  • Compact, contemporary design. Fits any décor.
  • Export models available.
  • Units available for ADA applications.

Made in U.S.A.



  1. Audio frequency response: Selectively shaped for maximum voice intelligibility.
  2. Audio power: Watts per amplifier (2 amplifiers)
  3.  Distortion: Less than 2%
  4. Listen mode: 20 dB compression
  5. Talk mode: Vox
  6. Microphones: Electret
  7. Power supply: Input: 120 VAC, 60 Hz Output: 15 VDC, 175 mA
  8. Other input power is available upon request.



  1. Outside assembly: Machined aluminum, anodized finish, tamper-resistant.
  2. Inside assembly: Machined aluminum, anodized finish, tamper-resistant.
  3. Size (both assemblies): 12 ½ in., W x 2 3/8 in. H x 2 3/8 in. D
  4. Weight: 2.5 lbs.
  5. Mounting: Counter-top
  6. Panel controls: No external controls
  7. specifications are subject to change without notice.