Hidden Hearing Loss and APD: Why ‘Normal’ Hearing Can Still Feel Hard

Two people with Hidden Hearing Loss

Author: Rosalie Machlin, Victorian Hearing Audiologist

Have you ever passed a hearing test, only to still find yourself saying “What?” in noisy cafés, struggling to follow conversations at work, or feeling mentally drained after social events? You’re not imagining things. While standard hearing tests can show everything is “normal,” some people experience real and persistent difficulties with hearing and processing sound. Two lesser-known but important conditions—Hidden Hearing Loss (HHL) and Auditory Processing Disorder (APD)—may be the reason. Understanding these hearing challenges is the first step toward finding the right support.

What is Hidden Hearing Loss?

Hidden Hearing Loss (HHL) refers to difficulty hearing in noisy environments—even when a standard hearing test shows your hearing is “normal.” That’s because traditional tests only measure hearing thresholds up to 8 kHz and don’t detect more subtle forms of damage.

The issue lies deeper, within the inner ear (cochlea), where tiny hair cells connect to the auditory nerve. In people with HHL, the synapses between these cells and the nerve can become damaged. These connections are critical for sending clear, detailed sound signals to the brain—especially in complex listening environments. When they’re compromised, the brain receives a distorted or incomplete version of what was heard, making speech harder to understand in background noise.

In short, it’s not that your ears aren’t picking up sound—it’s that the message isn’t getting through clearly. This disconnect is what makes HHL so frustrating and easy to overlook without the right testing approach.

Key Signs of Hidden Hearing Loss

Hidden Hearing Loss can affect your daily life even if your hearing test results are ‘normal’. You might notice that:

• You pass standard hearing tests but still often find yourself asking people to repeat themselves, especially in noisy environments like restaurants or busy streets.
• Following conversations in crowded or lively places feels mentally exhausting, leaving you tired or overwhelmed after social events.
• The problem isn’t that sounds are too quiet, but that speech lacks clarity or sounds distorted, making it hard to understand what’s being said.

If these experiences sound familiar, it could be a sign that Hidden Hearing Loss is impacting how you process sounds in complex listening situations.

How is Hidden Hearing Loss Identified?

Traditional hearing tests often miss Hidden Hearing Loss because they only measure hearing sensitivity up to 8 kHz. To detect HHL, audiologists may use specialised assessments such as:

• Extended high-frequency (EHF) audiometry: Testing hearing above 8 kHz to identify subtle changes.
• Speech-in-noise tests: Measuring how well you understand speech against background noise.
• Otoacoustic Emissions (OAEs): Checking the health of the inner ear hair cells by recording sounds the ear produces in response to stimuli.
• Working memory screen: Evaluating cognitive abilities related to processing and remembering auditory information.

Who’s at Risk?

Certain groups are more likely to experience Hidden Hearing Loss, including:

• People frequently exposed to loud noise, such as musicians, factory workers, or those who regularly attend loud events.
• Adults over 30, as age-related changes often first appear in extended high-frequency hearing before affecting standard frequencies.

What Is Auditory Processing Disorder (APD)?

Auditory Processing (AP) refers to a person’s ability to “process” auditory (verbal) information. It’s about what we do with what we hear, not just our ability to detect sound.

When someone has Auditory Processing Disorder (APD), they can detect sound normally but cannot make full use of what they hear. Children with APD often have trouble understanding auditory information even though their hearing is normal.

Importantly, APD is not caused by higher-order language, cognitive, or related disorders, although it can be associated with difficulties in language, learning, and communication skills.

Key Signs of APD

• Difficulty following verbal instructions
• Misunderstanding speech, especially when background noise is present
• Trouble with sound localization (figuring out where sound is coming from)
• Issues may arise even in quiet one-on-one conversations

How Is APD Identified?

Diagnosis is based on a comprehensive test battery and can include:

• Auditory figure-ground testing
• Binaural integration and separation tasks
• Memory and attention assessments

APD is often identified in children, but adults can be affected too—especially if they’ve had lifelong listening difficulties.

Finding the Right Support with Victorian Hearing

Understanding the difference between Hidden Hearing Loss (HHL) and Auditory Processing Disorder (APD) is key to ensuring the right diagnosis and effective support. For example, a student who mishears instructions in class may benefit from auditory training designed for APD, while an adult overwhelmed by noisy meetings might find relief with hearing technology that enhances high-frequency sounds associated with HHL.

Early identification of both HHL and APD is essential. Hidden Hearing Loss, in particular, can serve as an early indicator of age-related hearing decline. Routine testing that includes extended high-frequency thresholds can help detect these subtle changes before they appear on traditional hearing tests.

What Can Help?

For Hidden Hearing Loss:

• Remote microphone systems or low-gain hearing aids that amplify subtle sound details
• Regular extended high-frequency (EHF) monitoring for those exposed to loud environments or experiencing age-related changes
• Auditory training to strengthen listening skills and working memory

For Auditory Processing Disorder:

• Auditory training programs tailored to improve processing abilities
• Classroom accommodations such as captioning or written instructions
• Remote microphone systems to reduce background noise and improve speech clarity

Hearing is about more than just detecting sound—it’s about making sense of it. Whether the challenge stems from hidden damage in the ear or from how the brain processes sound, help is available. If you or someone you care about struggles to hear clearly despite “normal” hearing tests, exploring the possibility of HHL or APD with the experts at Victorian Hearing could be the first step toward clearer communication and better quality of life.

With eleven clinics across Melbourne, you are sure to find a friendly smile and support from the Victorian Hearing team. Call (03) 9558 8842 or book online.

References:
1. Hunter LL, et al. Extended high frequency hearing and speech perception implications in adults and children. Hear Res. 2020;
2. Wang M, et al. Extended high-frequency audiometry in healthy adults with different age groups. J Otolaryngol Head Neck Surg. 2021;50(52).
3. Mishra SK, et al. Extended High-Frequency Hearing Loss and Suprathreshold Auditory Processing. Ear Hear. 2025.