In the same way that an audiology exam is not simply testing pure tones, an audiometer is not simply a device that audiologists use to perform hearing tests. For the audiologist, the audiometer is an indispensable tool.
An audiometer is a specialized piece of equipment that requires investment. Whether you are making the purchasing decision for yourself or on behalf of a clinic, the audiometer you choose must meet your specific needs. This article highlights some common audiometer types and their benefits to help you choose the right one for you.
Screening audiometers vs. diagnostic audiometers
Before choosing your audiometer, you must consider both the types available and the range of patients you intend to serve. The type of audiometer you choose depends on both your current and future clinical needs; if you are planning to serve a wider range of patients or perform a wider range of tests, you may consider an audiometer with more functionality.
It is important to differentiate between screening audiometers, diagnostic audiometers and clinical audiometers.
As the simplest common process, screening requires the least from an audiometer – pure tones and perhaps speech testing functionality. Screening audiometers may be standalone or portable but are certainly restricted to a single channel (more on two-channel audiometers later).
Automated screening is possible with some audiometers. With regard to automated screening, this is possible if, for example, you choose a portable tympanometer and add audiometric functionality. One such solution is the Bio-logic AuDX PRO FLEX, a pediatric-based handheld tympanometry/audiometry/OAE combined device.
Diagnostic audiometers, on the other hand, are primarily for assessing a patient for hearing impairment and perhaps fitting hearing aids. The audiometer you choose can therefore depend on whether your audiology practice is within a larger organization or private, or whether the audiometer will be used at a fitting clinic or for ear, nose and throat (ENT) referrals.
If your primary focus is fitting hearing aids, the Aurical Aud has built-in tools for fitting that allow you to achieve a more efficient footprint, and can be combined with verification for completing best practices, not only for the diagnostic hearing test but also the fitting of the hearing aids.
For more advanced evaluations, such as pediatrics, patients with auditory processing disorders, patients with complaints of tinnitus or patients who require cochlear implants, consider an advanced audiometer with maximum functionality, such as the Madsen Astera2.
Standard audiometer types
Historically, the placement of the audiometer in the audiology clinic has been restricted because of the size of the equipment. However, with advances over the past few decades, audiometers are smaller and in some cases, portable.
When considering a portable audiometer, ask yourself how often you travel to provide itinerant services. If you are a private practice dispenser, you might travel to nursing homes or clinics, or travel to health fairs to perform hearing tests. In this case, you would need a reliable, portable audiometer that can perform tests in these situations.
You might not have the same needs, however, if you are an audiologist at an ENT practice with a sound booth in a single location. Your needs as a clinician are the first step in making decisions for outfitting your clinic.
You should also think about which type of power source would work for you. While many modern portable audiometers use lithium-ion batteries, some still require an outlet. If you will be servicing locations that do not have access to power, for example, you will almost certainly need a battery-operated audiometer.
A clinical audiometer can refer to any instrument sufficiently versatile and accurate to meet the extensive clinical needs of the audiologist. Outside of automated screening, you can screen with essentially any diagnostic audiometer. With this type of audiometer, you can provide all the basics but add a layer of more comprehensive functions.
When thinking about which functions you need (and therefore, which clinical audiometer to choose), you can narrow down your search using questions about the types of patients you intend to interact with:
- Are you seeing adults only, or children too?
- If adults, are you seeing vestibular patients? Patients with complaints of tinnitus? Patients who experience difficulty understanding speech in noisy environments?
- If taking the pediatric route, are you seeing babies after they have failed newborn hearing screenings? Are you seeing children with speech delay and undiagnosed hearing loss?
- Are you seeing patients with intellectual or developmental disabilities, who may be more difficult to test?
- Are you seeing patients for fitting hearing aids?
The continuing reduction in size of microprocessors had led to smaller and smaller technological products, and audiometers are no exception. As a result, many clinics are starting to move towards PC-based audiometry.
The benefits of PC-based audiometry include integration with electronic medical records (EMR) for comprehensive reporting of results, patient management across specialties and being able to communicate results from audiology to ENT or neurology, or back to family practice. In the US, in particular, this integration is a critical component for many medical providers.
PC-based audiometers also integrate seamlessly with NOAH and Otosuite. If you have a patient that visits regularly, having easy and continuous access to their data for review and use in other sessions can save you a lot of time. The audiologist performing hearing aid evaluations can also use information from diagnostic sessions to fit and verify hearing aids.
PC-based audiometers are particularly useful for hearing aid verification. They remove the need to re-enter audiograms repeatedly into different platforms in order to complete procedures. PC-based audiometers store your initial data and allow you to use it throughout the patient journey. Not only do PC-based audiometers save a lot of time, but they also reduce the rate of error that comes with attaching records to the correct patient.
A standalone audiometer is limited in functionality and is designed to run using proprietary software. Many modern standalone audiometers come pre-installed with wav files of basic adult and child speech audiometry tests, such as spondee word lists, CID W-22 and NU-6.
In a standalone audiometer, you can use Otosuite as a standalone program, to store local data. You do, however, have the option to select a module within NOAH to make data available for other applications.
Channels and calibration
It is also worth considering whether you need a one-channel or two-channel audiometer, and how often you will need to calibrate your audiometer.
When seeing occupational health or motor vehicle accident (MVA) patients, for example, you will require a two-channel audiometer to perform dichotic listening or Stenger tests. You will also need two channels for cochlear implant evaluations to assess speech and noise. Natus’ Madsen Astera2 comes with special features for testing pediatric patients and tinnitus patients.
Finally, the frequency with which you should calibrate your audiometer depends on regulatory guidelines, which vary by state and country. At minimum, however, it is recommended that you should calibrate your audiometer once per year.
In the end, an audiometer is a long-term investment., and so you should consider not only your current needs but also your future ones. When making the investment in an audiometer, it is worth considering investing more now to save time and money in the long-term.