About Us

A history of innovation and expertise

Our Beginnings

More than 60 years ago, with the help of a police officer, SONITROL was founded with the goal of reducing false alarms and increasing criminal apprehensions. 

In 1960, Robert Baxter, of Anderson Indiana, installed microphones within the walls of a building to listen for termites and pinpoint their location. Many sound-related inventions later, Baxter met Al Cronk, a local police officer, in 1963. 

Frustrated with the current systems that seemed to let the perpetrators get away, Cronk joined with Baxter to develop ideas for a new alarm company. Baxter responded with the audio sensor, and so SONITROL was born as a security company in 1964. 


Today, SONITROL continues to offer cutting-edge security when and where you need it most, with service in cities all across North America.

With a growing national and international network serving customers of all sizes, we have the expertise to tailor an ideal solution for your security requirements - all monitored by our 24/7 Central Station.

A heritage of technical innovation

Antique image of Bob Baxter

Robert Baxter Incorporates “SONITROL”

From words “sound” and “control,” “SONITROL” is incorporated by Baxter to manufacture and market his innovations.


Robert Baxter Meets Al Cronk

Baxter meets Cronk, a local police officer who owned an alarm company. The pair joins together to found SONITROL the following year.

Black and white photo of Al Cronk
Black and white photo of Sonitrol's centralized control station

SONITROL Develops Its Network

SONITROL develops a franchise concept and distribution network, becoming the largest franchise security network in the United States.


SONITROL Sells Its First Franchise

In 1968, SONITROL sells its first franchise in Detroit, Michigan, which sells its first school security system. This first franchise is the start of several key SONITROL individuals.

Vintage photo of woman at control station
Black and white photo of Harry Fleming

SONITROL Changes Ownership

Purchased by a venture capital group in Washington, D.C. owned by Harry Flemming, the SONITROL Corporation changes ownership.


SONITROL Warranty Program Introduced

In 1978, SONITROL introduced our Warranty Program, which offers the industry’s strongest guarantees.

Sonitrol warranty seal

What sets SONITROL apart?

State-of-the-art, customized solutions

We design modular, scalable solutions to fit the unique needs of each industry, organization and facility we serve.

Industries We Serve

We Provide Solutions for Many Industries, Including:

Our National Accounts Program

Meet your needs for local knowledge and national coverage.

With service in over 180 cities across North America, SONITROL can provide a consistent, standardized experience to our multi-facility corporate clients. As part of our National Account Program, you can count on us for centralized management and billing, as well as a dynamic team of sales professionals, a technical operations manager and a program administrator.

Explore Our National Accounts Program

The SONITROL Warranty Program

Shouldn't you trust your security to the only technology that trusts itself?

We’ll detect and report any forcible entry made to the interior of your building while your SONITROL system is in operation, or the SONITROL Warranty will pay, replace or repair any loss or damage to covered goods caused by the forcible entry up to $20,000 (depending on location and account).

Learn More About Our Warranty Program

Get Started With SONITROL

Whether you’re starting from scratch or updating an existing system, get started with SONITROL today for cutting-edge security, when and where you need it most.