How Audiologists Use Real Ear Measurements for Precise Hearing Aid Fittings

When you receive a new hearing aid, getting the right fit involves much more than physical comfort. At Victory Hearing & Balance, we use Real Ear Measurements (REM) - a scientific approach that validates your hearing aid's performance directly in your ear.

What Makes Every Ear Unique

No two ears are identical. The size and shape of your ear canal affect how sound travels to your eardrum. These unique characteristics mean that hearing aids must be programmed differently for each person, even if they have similar hearing test results.

Think of your ear canal like a room with its own acoustic properties. Sound bounces off the walls differently depending on the room's size and shape. This same principle applies to your ear canal - its unique dimensions influence how sound reaches your eardrum.

Understanding Real Ear Measurements

Real Ear Measurement is an objective way to verify that your hearing aids deliver the right amount of amplification at each frequency. During this process, we place a tiny microphone in your ear canal to measure the actual sound levels your hearing aid produces near your eardrum.

The measurement process includes several steps:

1. Base Measurement: We measure your ear canal's natural acoustics without the hearing aid.
2. Target Setting: Based on your hearing test results, we establish target amplification levels for different frequencies.
3. Verification: With your hearing aid in place, we measure the actual sound output and compare it to these targets.
4. Fine-Tuning: We adjust your hearing aid settings until the measured output matches your prescription targets.

Why Standard Programming Falls Short

Hearing aid manufacturers provide default settings based on averaged ear canal measurements. But relying solely on these defaults misses the mark for most people. Research shows that hearing aids programmed without REM often deliver too much or too little amplification in certain frequency ranges.

Studies indicate that hearing aid wearers prefer settings verified through Real Ear Measurements over standard programming. The American Academy of Audiology and American Speech-Language-Hearing Association recommend REM as a best practice for hearing aid fittings.

The Technical Side of Real Ear Measurements

Real Ear Measurements involve several specific measurements that help us achieve precise hearing aid fittings:

Real Ear Unaided Response (REUR)‍

First, we measure how your ear canal naturally responds to sound without a hearing aid. This baseline measurement captures your ear's unique resonant characteristics. Each ear canal amplifies certain frequencies differently - typically boosting sounds between 2000-3000 Hz by 15-20 decibels.

Real Ear Occluded Response (REOR)‍

Next, we measure how sound travels through your ear canal when the hearing aid is in place but turned off. This tells us how much the physical presence of the hearing aid changes your ear's natural acoustics.

Real Ear Aided Response (REAR)‍

Then we measure the actual output of your hearing aid while it's running. We test this using different input levels:

• Soft sounds (50-55 dB SPL)
• Conversational speech (65 dB SPL)
• Loud sounds (80-85 dB SPL)

Real Ear Insertion Gain (REIG)‍

By comparing REAR to REUR, we calculate the exact amount of amplification your hearing aid provides at each frequency. This must match prescribed targets based on your hearing loss.

Speech Mapping‍

We use real speech signals to verify how well your hearing aid processes actual speech sounds. This shows us whether important speech sounds fall within your audible range.

The measurement process includes specialized equipment:

• A calibrated probe microphone with a silicon tube (0.9mm diameter)
• A reference microphone to monitor input levels
• A sound field speaker positioned at 0° azimuth
• Real-time measurement software that displays:
  • Input/output curves
  • Target matching accuracy
  • Speech audibility maps
  • Compression response

During testing, we position the probe tube approximately 6mm from your eardrum. This placement matters - variations of even 2-3mm can affect measurement accuracy at high frequencies. We mark the tube to maintain consistent placement between measurements.

The software displays these measurements on a graph showing:

• Frequency (Hz) on the horizontal axis (typically 125-8000 Hz)
• Sound pressure level (dB SPL) on the vertical axis
• Target curves based on your prescription
• Actual measured output
• Speech spectrum zones

Beyond Basic Fitting

Real Ear Measurements support ongoing care:

• Different Listening Environments: We can verify performance with various types of input sounds, from soft speech to loud environments.
• Multiple Programs: Each program in your hearing aid can be verified to work as intended.
• Device Changes: When you upgrade to new hearing aids, REM helps maintain consistent sound quality.

What to Expect During Your REM Session

Your REM appointment at Victory Hearing & Balance typically involves:

1. A brief ear examination to check for wax or other issues
2. Placement of a thin probe tube in your ear canal
3. Measurement of your ear's natural acoustics
4. Testing with different sound levels while wearing your hearing aids
5. Adjustments based on the measurements and your feedback

The entire process takes about 10-15 minutes per ear and causes no discomfort.

Making the Most of Your Hearing Aids

Real Ear Measurement represents just one part of our comprehensive approach to hearing care. Dr. Jill Davis combines this technical precision with careful attention to your listening needs and lifestyle. This partnership between precise measurement and personalized care leads to better outcomes.

When to Schedule REM

Consider scheduling a Real Ear Measurement session if:

• You're getting new hearing aids
• Your current hearing aids don't sound quite right
• You've experienced significant changes in your hearing
• It's been over two years since your last REM verification

Taking the Next Step

At Victory Hearing & Balance, we believe in combining technical excellence with personalized care. Real Ear Measurements provide the scientific foundation for successful hearing aid fittings, but they work best as part of an ongoing relationship with your audiologist.

If you'd like to learn more about how Real Ear Measurements can improve your hearing experience, contact our office at (512) 443-3500. Dr. Davis and our team look forward to helping you achieve the best possible hearing outcomes through precise, evidence-based care.