Speech Technology Magazine


Testing the Voice Input Waters

Continuously advancing technology has enabled microphone companies to mold devices to the constantly changing needs of the end-user
By Kenneth White , Roberto Sicconi , Harvey Ruback - Posted Jun 30, 1999
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Continuously advancing technology has enabled microphone companies to mold devices to the constantly changing needs of the end-user Over the past couple of years we have seen an increase in the number of companies entering the speech technology market. With advancements being made in leaps and bounds in speech technology itself, and the constant expansion of computers beyond the desktop, the speech boom is expected to continue. With growth in speech applications comes an increased need for a wide variety of voice input devices. Producers of microphones and headsets are listening to the feedback of consumers and molding new products to meet their needs. Advances have been made in many areas, including noise reduction, comfort and mobility. The following are just a few examples of the many products on the market today.

Emkay Innovative Products Radio Frequency Computer Headset
Emkay, a Knowles Electronics company, offers the RF Wireless Headset, a single channel, full duplex system, with a transmit range greater than 20 feet. Designed for the most demanding of applications, the RF Wireless Headset's low power consumption gives users a very powerful product capable of performing up to 10 hours between recharges. Furthermore, its featherweight construction, and unique earloop design ensure a more comfortable fit. The RF utilizes Emkay's high quality Noise Canceling Electret Microphone - the industry's top-rated microphone element - allowing it to be used in the noisiest of environments and still deliver maximum performance. The headset has been designed for use in PC voice recognition, computer telephony and Internet telephony. Emkay recently received two awards for the RF Wireless Headset. The company received the Best of AVIOS ‘98 Award for its RF Wireless Headset in the Best Desktop Application Category and the ‘Peak Performance’ Award from the SpeechTEK ‘98 exhibition in New York. For more information contact Emkay at 847-952-3964 or visit their website at http://www.emkayproducts.com.

Telex USB Digital Headworn H-531
Telex is now offering a USB digital microphone for speech dictation applications. The H-531 USB Digital Headworn Microphone delivers pure digital signals to the speech recognizer and eliminates the performance variations inherent in analog sound cards. The headset also includes Acoustic Noise Cancellation technology to cancel background noise that can degrade speech recognition performance. USB has benefits for microphones beyond ease of use. Speech recognition software performance is greatly affected by the quality of the audio signal. Software developers have had a difficult challenge dealing with the wide variations in performance and quality of analog sound cards. With a USB interface, the voice signal bypasses the soundcard with direct digital input to the USB bus. In fact, there’s no need for a sound card at all. For speech recognition software developers, USB is significant because it provides a high-quality, digital input method that is consistent across all PC system platforms. It is the most consistent and reliable input method for PC microphones. For more information contact Telex Computer Audio Group at 612-887-9280, or visit the Telex website at http://www.computeraudio.telex.com.

Andrea Electronics Corporation NC-8 Head-Mounted Microphone
The Andrea NC-8 head-mounted microphone was designed to meet the needs of the speech industry’s leading software publishers and PC original equipment manufacturers (OEM), including IBM Corporation, requiring a lightweight and cost-effective microphone solution. Since the product’s introduction, IBM has purchased the NC-8 microphone to be packaged and sold with select IBM Aptiva PCs worldwide and with IBM’s speech-enabled Edmark Suite. The Andrea NC-8 microphone is a high performance, ultra-lightweight, head-mounted, noise canceling microphone with a flexible boom. The NC-8 microphone's unique design allows users to easily position the microphone for optimum voice input. In addition, the microphone's noise cancellation technology increases voice intelligibility and speech recognition accuracy, particularly in noisy environments. For more information contact Andrea Electronics Corporation at 800-442-7787, or visit the Andrea website at http://www.andreaelectronics.com.

Labtec LVA-7370 ClearVoice Collar Microphone
As an alternative to a headset, Labtec offers the LVA-7370 ClearVoice Collar Microphone. It is designed to fit comfortably and discreetly around the user’s neck or inside the collar, properly positioning the microphone element in a near-field proximity to the user. This positioning provides the quality input signal required for effective speech recognition. Since many PC users already have multimedia speakers, and many speech recognition applications do not require audio feedback, the design eliminates speaker elements used in conventional headset designs, resulting in a lighter weight, more comfortable alternative. The product also features a mute control, quick cord detach, and a monitor mounted "cradle" with wire management for added convenience. The LVA-7370 ClearVoice' Collar Microphone was awarded with the Red Dot for Highest Design Quality from the Design Zentrum Nordrhein Westfalen, a leading European institution in the field of design promotion based in Essen, Germany. The award is the second award in six weeks for Labtec, which also won the 1999 iF Product Design Award for superior design. For more information contact Labtec at 360-896-2000, or visit the Labtec website at http://www.labtec.com.

Shure Wireless TCHS
The new TCHS system from Shure meets the wide-ranging functional needs required for speech recognition, medical, legal and business dictation, PC based video conferencing, computer telephony and command and control operations. Providing the freedom of hands-free, untethered operation, the Sound Blaster Certified system includes a body pack-type transmitter, receiver, headset/microphone and power supply. A six-foot interface cable comes standard with each unit for connecting the headset to the transmitter. Power is supplied by a nine-volt battery, which is also included. For more information contact Shure Brothers Incorporated, 222 Hartrey Avenue, Evanston, IL 60202, or visit the Shure website at http://www.shure.com.

Sennheiser m@m40 medi@coustic PC Microphone
The Sennheiser m@m40 desktop microphone is one of the 12 products recently introduced in the new medi@coustic Series, a multimedia line of consumer products for PC-based speech recognition, Internet communication, and multimedia audio applications that allows users to be untethered from their PC. Designed to optimize the way users both work and play on PCs, the m@m40 reduces background noise and focuses signal reception on the user’s voice. This omni-directional microphone has a frequency response of 40-12,500 Hz. For more information contact Sennheiser at 860-434-9190 or visit their website at http://www.sennheiserusa.com

GN Netcom/Unex SeleCT Computer/Telephone Switch for Headsets
Changing from the telephone to your computer with the same headset can be easily accomplished using the SeleCT Computer Telephone switch for headsets from GN Netcom/Unex. With the SeleCT switch, a headset user can easily move from using the telephone to working with multimedia, speech recognition and voice-over-Internet applications on the computer. The SeleCT switch is compatible with all GN Netcom/Unex products, including the wireless headset, MPA Satellite. For more information contact GN Netcom/Unex at 800-345-8639 or visit the GN Netcom/Unex website at http://www.gnnetcom.com

"Fly Me to The Moon"
Knowles Electronics, Inc., world leader in micro-transducers for the hearing aid industry, had already been in business for eighteen years when Frank Sinatra first recorded his famous song "Fly Me to the Moon", on June 09, 1964. Five years later on July 20, 1969, Sinatra’s hit song became a reality for Knowles when its BA/BB transducer landed on the Moon aboard Apollo 11. Knowles’ BA/BB was used as a microphone and receiver in the headset worn by the astronauts. As Hugh Knowles, founder of Knowles Electronics, said, "the world had heard the astronauts speak via a Knowles microphone." Thirty years later the same company, Knowles Electronics, but new division, Emkay Innovative Products, changed lyrics; this time, singing about Mars. On January 3, 1999, Emkay’s EK-3132 microphone was aboard NASA’s launch of the Mars Polar Lander (MPL), the first in a series of Mars lander missions in NASA's Mars Surveyor Program, which is scheduled to touch down on the surface of Mars on December 3, 1999. Aboard the MPL is the Mars Volatiles and Climate Surveyor (MVACS). The MVACS is a collection of instruments that will study the distribution and behavior of water on Mars and its role in Mars' weather and climate. The MVACS was built by a team of scientists and engineers led by the University of California, Los Angeles (UCLA), and includes the California Institute of Technology, Jet Propulsion Laboratory (JPL), the University of Arizona (UA), and the Max Planck Institute for Aeronomy (MPAe) in Germany. Also aboard the MPL is the LIDAR (Light Detection And Ranging), the first Russian instrument included on a US planetary mission. The LIDAR will study the distribution of dust in the atmosphere, under the direction of Viacheslav Linkin of the Space Research Institute in Moscow. Riding piggy-back on the LIDAR, is the Mars Microphone. The Mars Microphone is a small device, roughly 5 centimeters on a side and one centimeter thick (2 x 2 x 0.5 inches), weighing less than 50 grams (1.8 ounces) and using a small amount of power, less than 0.1 watts during its most active times. The Microphone’s task is to sample sound while the rest of the probe studies the soil, weather, and atmospheric dust. It will both listen (for periods of about 10 seconds each), and record occasional frequency spectrum information. The Mars Microphone was developed and implemented by a team from The Planetary Society, The University of California, Berkeley, Space Sciences Laboratory, and The Space Research Institute, Russian Academy of Sciences. The Mars Microphone consists of a microphone, plus digital electronics to acquire and store sound samples. The microphone chosen for the Project was Emkay Innovative Products’ EK-3132. Emkay’s microphone was selected for its small size and low power consumption. The EK-3132 is essentially flat from 100 Hz to 10 KHz and has a sensitivity of about -53 db (relative to 1 v/uBar). Its dimensions are only 4mm x 5.5mm x 2.2mm and it draws less than 50 uAmps from a supply voltage of 0.9 to 10 volts. The microphone is an electret type so the only power consumer is the internal FET amplifier. Furthermore, the noise level is only 23 db. According to Mars Microphone Team member, Mr. Henry Primbsch, Senior Engineer at The University of California, Berkeley, Space Sciences Laboratory, "Mars has an atmosphere (approximately 10-20 millibars of carbon dioxide) which supports sound propagation. We expect to hear an assortment of sounds such as lightning storms, sonic booms from meteors entering the atmosphere, wind noises, dust grains hitting the microphone, and instrument deployment operations such as the scoop digging up Martian soil. We are hopeful that we might even hear something we didn't think of." Because of the thin atmosphere on Mars, the sounds are expected to be much fainter than normal (like a person whispering). Nevertheless, laboratory experiments with the Emkay EK-3132 in a vacuum chamber pumped down to Mars surface conditions have demonstrated that acoustic signals within the frequency range of the human ear can be detected. Amplification in the EK-3132 will allow detection of even very low level sounds - usually unnoticeable in everyday life. For more information on Emkay Innovative Products, visit Emkay’s website: http://www.emkayproducts.com or Knowles Electronics: http://www.knowlesinc.com.

If You’re Using a Laptop for Speech Recognition…
Make sure your headset has enough power!

The most recent computer data indicated that laptop sales continue to grow at a faster rate than traditional personal computers. Recent findings show that laptop sales growth was double digits in 1998, representing 1 in every 5 PC’s sold in the marketplace. As the quality, power and miniaturization of the laptop have improved, it is now performing at a level once only achieved by desktops. However, laptops are specifically designed to conserve power and may not provide sufficient bias or voltage through the sound card to optimally power the microphone. "Noise canceling headsets" used in speech recognition require proper voltage for optimal microphone performance. A similar need exists with some desktop PCs. Is this problem solvable? Absolutely. One solution comes from VXI Corporation. When the bias problem with PCs and laptops became evident, VXI created the Parrott Translator™(Patent Pending).The Parrott Translator detects and "translates" the bias from the computer or laptop and supplies the microphone with the voltage needed to maximize the microphone’s performance. The translator also works with the headset microphone to shape its frequency response and provide a consistent input to the soundcard. The result is improved speech recognition performance. The next question posed for the laptop user is the following: Does the Parrott Translator really work? At PC Expo ’98, an initial meeting with VXI and Corel executives took place. As a result, Corel placed an initial order for Parrott Headsets. "When we switched to the VXI Parrott Headset, we noted a reduction in the amount of technical support calls we were receiving. The Parrott, with its built-in Translator, can solve the power output variations between the different manufacturers of sound cards. This eliminated a major technical support problem. It is an excellent product," said Kerry Williams, Executive Vice President for Manufacturing of Corel Corporation. For more information contact VXI at 630-742-2888 or visit the VXI website at http://www.vxicorp.com

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