Directional hearing instruments have experienced a renaissance in popularity during the last few years. Directional hearing systems—whether omni-plus-directional or dual-omni configurations—have been widely acknowledged as being the most reliable method of increasing signal-to-noise ratios in noisy environments. This section of The Hearing Review® is intended to provide readers with an update on the latest available directional microphone technology offered by both hearing instrument manufacturers and suppliers. The information presented here was provided by the participating companies upon request by HR.

To obtain more information about the following products, please circle the appropriate number on the Reader Service Card located between pages 10 & 11 and 74 & 75 of this magazine or contact the companies directly via the information listed below. Additionally, advertisers in this issue of HR have their Web sites, where additional product information can be obtained, listed on the last page of the magazine.

f04a.gif (1539 bytes) Audina Hearing Instruments
Audina, a privately owned Florida-based hearing instrument manufacturer, has a comprehensive product line that includes digital, programmable and conventional products, all available with directional technology. The company’s digital product line includes the Nueve digital and the Paragon 4 digital. These products are also available with Frontwave Directional Technology, which uses two microphone inputs along with time-delay circuitry to create a directional response. Orlando, FL: (800) 223-7700.

Authorized Hearing Systems
Authorized Hearing Systems (AHS) offers its programmable SoundChannel™ directional microphone option, designed to assist patients who experience “background noise.” According to the company, the option with programming response will improve communication in a variety of listening environments. The 2-microphone directional system is available in full shell through half-shell models. The company’s directional microphones are designed with an optimized directional sensitivity index and work well with the company’s digitally programmable product line. Plymouth, MN: (800) 247-4741.

Beltone Electronics Corp.
Beltone Electronics offers directional dual-microphone technology as a standard feature of its Prima Digital behind-the-ear instrument. The multi-memory Prima Digital is programmed with Beltone’s SelectaFit fitting software and can be set for directional and/or omni-directional operation. The Prima Digital is used as an integral part of the Beltone AVE. multi-media fitting system to demonstrate the benefits of directional technology in difficult listening environments. The dual-microphone is also an available option on the Optima Digital custom ITE. In addition, Beltone offers the D-Mic directional microphone on the Optima Full-Shell CSPII-P, K-Amp-P and Linear-P analog programmable instruments, and the Optima Class-D linear ITE. Chicago, IL: (800) 621-1275.

Electone Inc.
Electone’s AudioAIM™ directional microphone system is designed to improve speech understanding in the midst of distracting background noise. Its multiple microphone design maximizes the signal-to-noise ratio by attenuating background noise as it arrives at the port(s). While in directional mode, the system is said to amplify sounds from the front and provides attenuation of sound from behind and to either side of up to 6 dB. Changing the toggle switch toward the pinna accesses the omnidirectional microphone and provides the patient with the full spectrum of surrounding sounds. The system is available on Class A, Class D, Class D AGC-O, SDM, the Pointe and Sierra full shell models. Longwood, FL: (800) 432-7483.

Etymotic Research
Etymotic Research provides the sD-MIC™ microphone for ITE and half-shell aids. The microphone is a smaller version of the original D-MIC™, and features high noise reduction (AI-DI of 4.8 dB). The same noise reduction will soon be available in the smaller C-MIC™ series, designed for all ITE applications, including canal aids. The C-MIC, presented in cooperation with Microtronic, will be available in late-2001. All of Etymotic’s directional microphones use patented single-diaphragm directional construction which reportedly ensures stable, drift-free directional performance. Elk Grove Village, IL: (888) 344-6457.

General Hearing Instruments
General Hearing Instruments currently offers a directional microphone on standard full-shell and low-profile ITEs. The microphone, which is designed to improve speech intelligibility in noise, attenuates sounds from the sides and the rear. According to GHI, when noise comes predominantly from a direction opposite the signal, the improvement can be as much as 20 dB. When noise comes from all directions, an improvement of 3-6 dB can reportedly be experienced. The result can be a 30-55% improvement in understanding speech in sentences when compared with scores obtained with omnidirectional microphones, according to the company. New Orleans: (800) 824-3021.

Gennum Corp.
Gennum Corp. recently introduced DSP hybrids with embedded Frontwave™ functionality, which are designed to provide enhanced directional performance when combined with two microphones. Up to four memories can be programmed by the manufacturer or dispenser, and a wide variety of directional patterns can be employed, including cardioid, hypercardioid, supercardioid and bi-directional. Combined with the company’s calibration software, Frontwave™ reportedly compensates for any sensitivity and phase mismatches between the microphones, which is designed to eliminate the need for matched microphone pairs. In addition, the loss of low frequency sensitivity can be corrected for, according to the company. Burlington, Canada: (905) 632-2996.

GN ReSound Corp.
GN ReSound offers advanced digital dual microphone directional instruments for the hearing care field. The Canta7 series of instruments not only utilize Adaptive Directionality, they are reportedly the only instruments to provide Active Microphone Matching which automatically tracks and corrects changes in microphone sensitivity that occur over time. This ensures that the instrument works as well on the day of the fitting as throughout the life of the instrument. Canta7 provides this advanced directionality in the 780-D Power BTE, the 770-D BTE, the full-shell ITE and the smaller half-shell ITE. Bloomington, MN; 800-248-4327.

Intrason SA announces the launch of the Digison 621 MD, a new digital directional BTE. The Digison directional algorithm was developed in cooperation with researchers at the French National Center of Scientific Research. The new instrument allows the user to switch from omni-directional to multi-directional. This feature, combined with the company’s Speech Optimization System (S.O.S.®)—a 32-channel noise reduction algorithm— reportedly represents a technological advancement in the recognition of speech, particularly in noisy environments, according to the company. The instrument is distributed in the U.S. by United Hearing Systems. Choisy, France: website:

Knowles Electronics Inc.
The Knowles Electronics TP-series microphone combines an omni-plus-directional microphone into one package. Designed for both omni-directional and directional applications, the TP microphone features all-metal case construction and provides AI-DI of up to 5.2 dB (free field). In addition, the microphone needs only four wires to provide full omni-plus-directional performance, and
requires only two sound ports, saving hearing instrument manufacturers layout space and assembly time. Itasca, IL: (630) 250-5100.

Lori/Unitron & Argosy
Nexus’ digital dual-microphone directional system is designed to decrease sensitivity to sounds from the side and behind, reportedly improving the signal-to-noise ratio. Unifit allows the user to choose the appropriate directional polar plot and place it in any of the three memories during fittings. The digital dual-microphone, together with noise reduction, is designed to provide a solution to the problem of background noise. Axioms’ directional microphone system is designed to provide reduced gain for sounds originating from the sides and rear. The directional microphone can be activiated in any of the three memories via the company’s fitting software. Plymouth, MN; (800) 888-8882: website:

Magnatone offers the DirectVoice™ directional system, designed to eliminate the problem of dual-microphone drift with its single-microphone design. The system is activated by a D-slide™ switch which is easy for patients to activate. Two modes are available; directional mode, which is designed to maximize sounds originating in front of a patient and minimize sounds from behind them; and omni-directional mode, designed to amplify noise and speech equally from all directions. The system is available in the half- and full-shell models with the company’s TruVoice® 100% digitals and DigiPro™ programmable instruments. Casselberry, FL: (800) 327-5159

One of the greatest challenges for hearing instrument users is to understand speech in a noisy place. Micro-Tech now offers the DiRx Dual-Microphone Switchable Directional System. DiRx is available on a growing number if Class D circuits in Micro-Tech’s line of custom instruments, including Nx2 and NxN in both full-shell and half-shell models. The instruments include patented Micro-Tech Dual-Microphone Design, an electronic directional system, digitally optimized directionality individually programmed into each hearing instrument and a switch for omnidirectional and directional modes. Plymouth, MN: (800) 745.4327.

Microtronic offers a complete line of directional solutions, including single directional, directional-omni combinations, matched omni pairs, and the C-MIC™ and CC-MIC™ series microphones developed in partnership with Etymotic Research. The company offers: 9000 and 6000 (Thin 9000) series matched pair directional microphones; 100, 9000 and 6000 series single directional microphones; and the 6900 series directional-omni combination. Minnetonka, MN: (952) 543-8300.

Oticon Inc.
Oticon offers the DigiFocus II Direct, now available in a small, cosmetically attractive ITE. When background noise is a communication barrier, users will benefit from the new directional microphone that extracts maximum speech information from the incoming signal, according to the company. The user can actively choose between two programs: An omni-directional program to hear sounds from all sides, and a directional program to focus on speech directly in front of the listener. The incoming signal is processed with Oticon’s proprietary rationale, ASA2 , which is designed to enhance speech understanding in difficult listening situations. Somerset, NJ: (800) 526-3921.

Phonak Inc.
Phonak offers a variety of directional options, including the Claro™, which uses an adaptive directional system (dAZ). dAZ constantly scans the environment to identify the loudest source of background noise and adjusts the polar pattern to optimize the directional performance, according to the company. The company also offers AudioZoom™, which uses two omnidirectional microphones to improve signal-to-noise ratio. AudioZoom is available in ITE, half-shell, BTE and high-power programmable models. Also available is the Mini-D, the company’s smallest directional system, developed in answer to the demand for an effective directional system in custom instruments. Warrenville, IL: (800) 777-7333.

The hearing instruments in Qualitone’s digital line—Sapphire, Topaz and Aries—are all available with directional microphones in BTE, ITE and ITC models, along with many of the analog line of instruments. New digital products will be introduced this winter with the capacity to select the directional pattern to allow customization for various listening environments. The use of directional microphones has been shown to increase signal-to-noise ratio, thereby providing the potential to enhance hearing in noise, according to the company. Minneapolis, MN: (800) 328-3897.

Rexton offers a variety of directional instruments to meet the needs of many different types of hearing loss. The company’s 3D full-shell digital instruments use the latest digital technology to produce high sound quality. With three memories and six bands, 3D is designed to provide extensive fitting options, and a directional microphone comes standard on 3D BTEs. A directional microphone can also be added to the company’s two-channel, WDRC Sensation full-shell or half-shell digital hearing instruments. A full-shell directional microphone can be fit with the company’s D2 fully digital circuit. A directional D2 BTE is also available. In addition, the trimmer-adjusted, full digital gran-D hearing instruments can be enhanced with a directional microphone, and Horizon5 and Horizon3 full- and half-shell programmable ITEs can be fit with one. Plymouth, MN: (800) 876-1141.

Siemens Hearing Instruments
Siemens Hearing Instruments offers the Signia™ select and Prisma™ fully digital hearing instruments, and Music® and Infiniti 3™ analog programmable hearing instruments. Easy switching between directional and omni-directional modes is designed to give users enhanced understanding of speech in the presence of background noise. The design and multi-microphone capability generate an appropriate delay and subtraction of the signals for precise directional sensitivity. Available in HS, ITE and BTE models. Piscataway, NJ: (800) 766-4500.

Sonic Innovations
Sonic innovations offers its newest digital hearing instrument: NATURA 2 SE with DIRECTIONALplus!. Available on the company’s ITE and BTE models, NATURA 2 SE with DIRECTIONALplus is designed to provide a superlative system combining switchable directional microphone technology with Personalized Noise Reduction. When combined, these two technologies emphasize speech sounds from in front of the hearing instrument and de-emphasize noise originating from other directions. Salt Lake City, UT: (888) 423-7834.

Telex Communications
The Sontiva DLX Plus Model S42-D is the newest addition to Telex’s premium line of Sontiva digital hearing instruments. The S42-D features a Feedback Manager, a noise management system called VoiceSync and a multiple-microphone directional option. The directional microphone option is designed to help users face their most challenging listening situations with confidence by providing an improved signal-to-noise ratio. The instrument is packaged in a stylish new BTE case with a conventional volume control, SoftFlex sanoprene sides, memory push button and M-T-O switch. Burnsville, MN: (800) 328-8212.

United Hearing Systems
United Hearing Systems (UHS) announces the addition of the Intrason 621 MD digital/directional BTE to complete its line of directional hearing instrument products. The Digison directional algorithm has been developed in cooperation with researchers at the French National Center of Scientific Research. Features include: user operated multi/directional switch; Intrason’s proprietary Speech Optimization Syste
m (S.O.S.®), a 32-channel noise reduction algorithm; small case size with #13 battery; and sophisticated software that is designed to be user-friendly. Directional custom products are available in models as small as mini-ITC with digital, programmable and analog amplifiers. Central Village, CT: (800) 835-2001.

Widex combines the advantages of a directional microphone with CD-quality digital signal processing, automatic performance, sophisticated feedback management circuitry, long battery life, and the speech enhancing capability of the Senso Plus in the C9 and C19 directional models. The C9 BTE is the universal hearing instrument that provides directional performance for mild to moderately severe hearing loss, while the C19 BTE universal instrument provides directional power for more severe hearing loss. The C9 and C19 are both direct audio input (DAI) compatible. Long Island City, NY: (800) 221-0188.