September 1998

Advances In Headset Technology

BY DAVID EGENBERGER, GN NETCOM, INC.

It's a long way from old-fashioned telephone switchboards to James Bond and Jerry Maguire, but that's how far telephone headsets have come in the last 20 years. Once used almost exclusively by telephone operators at their consoles, headsets have become invaluable productivity tools in call center environments because of improvements made through mechanical, acoustical, electronic and materials technology. The ability for the user to remain hands-free is such a powerful benefit that headsets are now being widely adopted outside of the call center as well, fueled by their appearance in movies like Tomorrow Never Dies and Jerry Maguire.

The headset system works as an extension and enhancement of the traditional telephone handset and actually replaces the handset as the human interface to the telephone system. Technology continues to improve sound quality while making headsets smaller, lighter, more comfortable and more durable. Headsets enable call center agents to do their jobs professionally while improving their productivity and enhancing customer satisfaction. Ultimately, headsets enrich the customer and agent interaction because they improve communication while remaining undetected by the customer.

Microphone Sound Quality
The headset microphone transmits the agent's voice to the customer or prospect, and good sound quality helps the transaction move forward quickly and accurately - whether sales, customer service or technical support. The design of both the microphone and the microphone housing critically affects whether the customer hears just the agent's voice or becomes distracted by background noise in the call center. With the early lightweight headsets, the sound quality was not, in fact, as good as handsets, but users were willing to give up some sound quality in order to be hands-free.

Microphones come in three types: omnidirectional, noise canceling and ultra-noise canceling. Clear voice tubes, which feature omnidirectional microphones, amplify not only the speaker's voice but also all noise in the call center. Advancements in acoustical, materials and electronic engineering have replaced the voice tube with a housing and internal microphone design that picks up and transmits the speaker's voice while canceling out the background noise.

Another quality measurement for headset microphones is how well the voice travels over the telephone network. Any local or long-distance network degrades higher frequencies, yielding voice distortion on the receiving end. Because of the degradation of frequencies over the telephone network, headset microphones need to have a pre-emphasis on the frequency response so that the sound the customer hears better matches the input. Both microphones and microphone housings are now designed so the caller hears a more natural-sounding and clear conversation, resulting in improved user productivity and profitability.

Speaker Sound Quality
The quality of the headset speaker affects how well the headset wearer hears the caller. Human hearing goes from about 20 Hz at the low end to 20 kHz for someone with very keen hearing. The power of speech is centered right around 1,000 Hz, and most telephones and telephone network products in the old days were designed to provide that audio bandwidth. This transmitted most of the voice "information," but did not capture voice subtleties or inflections.

The early copper telephone networks had analog switches along with a narrow audio bandwidth, so headset manufacturers built their product to reproduce only what was on the network. Then, around 10 years ago, digital switches and fiber optic connections came into use, allowing a much wider bandwidth transmission through the voice network.

UNEX headsets were the first to take advantage of this wider bandwidth, ranging from about 300 Hz to 3500 Hz. Today voices sound truer, users have fewer problems with accents and speaking tones, and they are able to get more information correctly and quickly.

Amplifier Compatibility
Reliable and rugged, early headsets had an attached amplifier, powered by the network itself, so operators kept their own personal headset, which they plugged into the kneewell jack in an operator ACD station.

When digital PBXs and key systems were first introduced, the handsets had a four-pin modular plug requiring manufacturers to design a very different telephone interface. While the old system operated everything off the telephone network itself, the new systems did not, forcing the need for alternatives to power the amplifiers and circuits and accommodate a much wider range in transmit requirements. The results were confusing and expensive because each headset had to have its own amplifier and both had to be compatible with the telephone system. In 1989 GN Netcom introduced the first universal or multipurpose amplifier that had switches for carbon, AT&T and electret systems. Other manufacturers followed and, once again, headset users could have personal headsets that worked on any phone system.

Technology has allowed amplifiers to take on multiple functions formerly available only as accessories. For instance, the ACS SSA (Switching System Adapter) has an RNA (Representative Not Available) drop-circuit that redirects calls to available agents, dual headset ports eliminating the need for separate training equipment, and an under-the-desk mounting option to eliminate desktop clutter and cable tangling.

Perhaps the most important benefit of the multipurpose amplifier is its ability to protect a call center's investment in headsets. It is possible today to switch telephone systems without changing amplifiers or headsets - something that would not have been true just 10 years ago.

Amplifier Electronics
While amplification allows users to hear the customer better, it protects users from unexpected, loud noise bursts that come over the phone lines. Compression algorithms and protocols can identify voice and data bursts and act instantly to reduce the loudness. If, for example, the amplifier detects a loud fax signal, it compresses it down 10 decibels, making the sound safe for the ears.

Voice switching, an innovation from ACS, turns the amplifier on to transmit only when sound pressure is loud enough to indicate that the user is speaking, further eliminating background noise. The person on the other end of the line keeps focused on the caller rather than on background noise.

Ergonomics
Wearing a headset is a personal experience - and while anyone will pick up any telephone handset and use it, the same is not true with telephone headsets. In early headset designs engineers focused on the electronic components and used trial and error to create a comfortable product to wear. Now manufacturers keep databases of facial characteristics, especially ears, so they can see variations between ear sizes, location on the head and length from ear to the mouth. Optimizing the design to satisfy the largest number of people is critical when designing new products. The reliability and durability of hard plastics and fixed sizes must be balanced with ergonomic design for user comfort and appearance.

The technology in receiver elements has eliminated the need for additional components, allowing a more compact size. Now headsets are sleek, less conspicuous and less obtrusive. Users have choices of over-the-head or on-the-ear wearing styles and monaural or binaural speakers.

Wireless And Mobile
While not necessarily suitable for agents, many call centers currently use wireless headsets for their supervisors and managers, giving them the freedom to work with agents and still be available to customers. Wireless headsets enable the supervisors to be instantly responsive by answering their own phone while away from their offices in addition to saving call-back time. Supervisors can also plug into an agent's console to help with training or handling a challenging situation.

Headsets have also moved into the mobile market using the 2.5 mm port on many cordless, cellular and digital mobile telephones. People on the move can now enjoy the safety and productivity benefits long known to call center headset users.

Computer-Telephony Integration And Speech Recognition
As applications such as speech recognition, computer-based training and games create more audio interfaces for PCs, no one is willing to give up the ability to pick up the telephone and dial. Headsets are being introduced that are optimized for voice recognition software, featuring noise-canceling microphones, flexible microphone booms for better custom positioning, and styles that are comfortable to wear all day. As evidence of true computer-telephony integration, a small headset switch is available which allows the user to change from telephone set to computer use without having to purchase additional amplifiers, preserving the equipment investment.

The Next Generation
At GN Netcom, Inc., we believe that a clear and strong focus on research and development using the most advanced technology available can provide headset users with the highest quality and most professional productivity tools possible. Several products are currently in development which will decrease average work time for inbound call centers and enable outbound agents to carry on conversations with quiet lines, creating a better atmosphere during the sales conversation. Headsets and headset amplifiers will literally add sound quality using more sophisticated signal processing that will allow more complex compression and voice switching. Technology innovations will add to the intelligibility of speech, increasing the effectiveness of voice recognition software.

Ergonomic headset improvements are constantly in development. New materials that will lighten headsets are regularly being introduced. Adjustable, flexible, customizable wearing styles - styles that will conform to the user's personal preference - will soon be available. Contours will become more aesthetically pleasing.

There will always be the need to hook up the user to the network. The interface, however, will probably change. The desktop phone is on its way out. ACD stations have already become small boxes that sit next to or on top of PCs. Today that interface is becoming part of the headset system.

While James Bond and Jerry Maguire may think they are at the cutting edge of telecommunications advances, call center experts know they are just following in footsteps of the real headset innovators.

David Egenberger, Senior Product Marketing Manager for GN Netcom, Inc., is responsible for development of product programs for the ACS, GN Netcom and UNEX brands of headsets. GN Netcom, Inc., headquartered in Nashua, New Hampshire, designs, manufactures and markets high-quality telephone headsets, accessories and specialty products for the telecommunications industry.