Figure 1. The portable FM soundfield system is designed to sit on the student’s desktop.
It’s not something a hearing care professional notices right away upon visiting a classroom. The teacher is obviously wearing a microphone and a transmitter hooked on her belt, but you can’t spot anyone with a body-worn FM system. After being there for a while, however, you notice a few desks with little black bags sitting on top. Roughly the same size as a pair of soda cans sitting side by side, the bags look a bit small and plain for lunch bags.
In the mid-’90s, Phonic Ear began receiving requests for tips on how to construct a personal desktop amplification unit by using a computer speaker hooked up to the Easy Listener Personal FM system. Though this type of makeshift system worked, it was more than a little unwieldy, not to mention difficult to move from place to place, and the speakers drained batteries almost as quickly as new ones could be put in.
The Portable FM System
Sensing that there was a market for a portable personal amplification device, Phonic Ear began designing a product to take the place of the above makeshift system. Students representing HiP Magazine, a publication for young people with hearing impairment, came to the company’s headquarters to partake in a focus group, and ended up staying to act as product managers for a day. They were asked to stipulate the features they wanted in a desktop amplification system. Right away they knew what they did not want—a big box that looked like an amplification device. They also insisted that the device include some room for storage, since it would be taking up room on their desks. As for the technology, they left that up to the engineers.
What came out of the session was the Toteable sound field—a small, portable, and inconspicuous way to bring a teacher’s voice closer to the student who needs it. Weighing less than 2 pounds and having a height of about 5 inches, the FM system was designed to be everything envisioned by the students. A prototype was unveiled at AAA in 1998, although the product wasn’t available until the fall of that year.
Basically a sound field system in a small bag, Toteable raises the signal-to-noise ratio (SNR) so that the teacher’s voice is always audible and easy for the student to focus on. The device uses a body-worn receiver that’s tucked inside the bag to transmit the teacher’s voice to an individual student or a small group. The student plugs either the Easy Listener PFM or Solaris PFM receiver into a jack inside the Toteable, then places the bag on their desktop. They then turn on the unit and adjust the volume to hear the teacher’s voice (who’s wearing an Easy Listener or Solaris transmitter). The transmitter, receiver, and the speaker itself all occupy a specific place in the bag and all are recharged by plugging the wall unit charger into one clearly marked charge jack inside the bag.
Uses of a Portable FM System
The system is designed to be used in any situation that a personal FM system or a soundfield amplification system would be used. The same studies that have shown the benefits of classroom sound field also support the use of this device.
Any situation where background noise might hinder a student’s ability to understand or focus on the teacher, the FM portable device is appropriate. Though it is most often used for students with mild-to-moderate hearing loss either in place of, or in addition to, personal hearing instruments, there are many other instances where a better SNR makes a difference. Children with cochlear implants benefit because the system can bring in sound from beyond the range of the microphone while also minimizing the effects of background noise. It does not require a patch cord and, since students do not plugg anything in, they can still use their ear-level microphone.
Students with auditory processing disorders are often prescribed a multi-pronged approach for helping them to learn (for detailed information on this subject, see the article “Gauging the efficacy of CAPD Treatment” in the September 25, 2000 issue of Advance for Speech-Language Pathologists). One of the environmental modifications, aside from preferential seating, is soundfield amplification.
The system is also useful for applications outside the realm of hearing-impairment. For those students with attention deficit disorders (ADD) or learning disabilities, the FM system works by keeping them focused. Since these students often have trouble attending to the desired signal (ie, the teacher’s presentation) if it is diluted by ambient noise, the FM system helps them ignore auditory distractions. Another area where this system has been effective is in the English as a second language realm, where studies have found that a stronger speech signal greatly helps these students in less-than-optimum listening environments.
As students get older, they often refuse to wear an FM system because it singles them out. Since the Toteable is discreet, it is designed to provide a way for these children to receive the benefits of a better sound signal without looking different. It can also be shared by multiple students in a single classroom. Additionally, these types of systems are available to the whole class, so anyone can take advantage of the benefits—including those who have colds or ear infections.
In 2002, Toteable got a radical redesign that has introduced many improvements, including a more powerful, higher quality speaker. The newer model now has an acoustic power output of 126dB, 1kHz, vs the older version, which had an output of 80dB, 1kHz. This also gives it a better frequency response with more lows for a natural, warm (not tinny) sound. Also, to prevent occasional feedback, the speaker now has a filter with predetermined settings. The more powerful speaker called for a battery upgrade so the system includes Nickel Metal Hydride batteries, which put out 1600 mAh versus the old 950 mAh. Due to more energy output from the speaker, the battery life has stayed about the same: about 53 hours at volume setting #5, 29 hours at volume #7, and 7 hours at volume #9.
The aesthetics of the system have also been updated. The case grew to house the larger speaker, the corners are now rounded, and there are clearly marked slots inside the bag for all the components. The on/off/volume control is easier to access now that it’s placed on the front of the bag. The Toteable is still padded, but the basic structure is now a flexible, hard-shell case with a zipper top. Subject to durability tests during manufacturing, the system withstood being dropped over 10 times from a height of 10 feet without any problems.
When prescribing a desktop amplification device, the main factors a hearing care professional must consider are: the distance a child sits from the teacher; the teacher’s style (ie, very mobile or fixed); and the amount and intensity of background noise. Additionally, the hearing care professional needs to determine if students are currently using any other form of hearing instrument/cochlear implant or if they already use an FM system. Any child will benefit from hearing the teacher better, and this is just one more option for enhancing that signal to provide the best learning experience possible.
This article was submitted to HR by Staci Fritz, copywriter at Phonic Ear, Petaluma, Calif. Correspondence can be addressed to HR or Staci Fritz, Phonic Ear, 3880 Cypress Dr, Petaluma, CA 94954-7600; email: [email protected].