Meeting the Demands of Voice Communication Systems

Loud and clear is often the goal when it comes to a voice communication loudspeaker or audio system. That’s easier said than done and delivered. Plus, it requires thoughtful coordination between a customer and its OEM audio manufacturer because a solution that works in one place will not necessarily meet the same performance requirements in another due to the impact of both the physical space on the sound waves and the existence of competing sounds.

“One of the first products that MISCO ever manufactured was an 8-inch speaker for a ceiling paging application,” says Dan Digre, President and CEO of MISCO. Over its more than 75 years in business, MISCO has developed thousands of solutions that achieve high voice intelligibility by investing in design and engineering expertise and the testing equipment and processes required to ensure a prototype’s performance and a final product’s quality.

Sensitive to Critical Frequencies

When it comes to an audio system that will have voice communication as a primary function, it’s important the speakers have a high sensitivity and perform well over the frequencies between 125 hertz and 7 kilohertz—the typical range of the human voice.

Along with achieving the desired frequency response, an audio manufacturer will also be looking at the resonant frequency of a speaker—the specific frequency at which the speaker naturally vibrates most easily and generates the greatest volume for a given input signal. With a voice communication speaker, a resonant frequency is typically somewhere between 200 hertz and 700 hertz.

High sensitivity is important in a loudspeaker for voice communications because it gives a system a dynamic and detailed sound profile, which improves clarity, especially in noisy environments. High sensitivity also results in a system that is efficient and needs less electrical power from the amplifier to achieve a certain volume level.

In a public address system or intercom, where the amplifier is powering many speakers over a distance, high sensitivity means less power is wasted in the cables and the amplifier can deliver clear audio to all the speakers.

Voice Communication Solutions

For instance, the OK83 from MISCO is a coaxial speaker with an 8-inch cone and a 3-inch tweeter that has a sensitivity rating of 97 decibels per watt per meter. This speaker is widely used in paging systems, public communications, and background music applications.

“MISCO’s unique ability to design high-sensitivity drivers that meet the requirements of 94, 97 to 100 decibels is an important feature of MISCO’s speakers,” says Dan. “We have the test and measurement equipment to not only measure on-axis frequency response but [also measure] off-axis response, polar plots, balloon plots, the data that’s necessary to give architects and engineers EASE files, which they will use for modeling these speakers into the arenas, concert halls, airport concourses, or schools they’re working on.”

The OK4 4-inch series from MISCO is an ideal solution for low-level distribution and paging systems. Their rugged steel frames and cones, created from treated cloth, make them durable. If a system is going to be outdoors or in a high-humidity environment and needs good ingress protection, these speakers are also available with waterproof cones and waterproof gaskets.

The OK4 line is available with a line-matching transformer that could work in a 70- or 25-volt system.

“With MISCO’s broad line of ceiling speakers for paging, background music, and voice communications, it’s likely we have an off-the-shelf solution for your application, whether that’s a ceiling grill design or a speaker with a back box,” says Dan. “But if you need something custom-designed, reach out to us and we can work with you to deliver the solution you need.”