Thinking differently about how we describe hearing loss

Even though I have been an Audiologist for many years, I frequently describe myself as a perpetual student, still wanting to learn more about the science of Audiology and remaining open to thinking about “all things hearing” in new and different ways.

One topic that I recently learned more about is how we define and describe hearing loss. Let me explain in a little more detail.

How WHO threshold-based categories shape (and limit) our understanding

We typically describe hearing loss using the audiogram. We group each hearing loss category in terms of the perception of pure tones in dB HL at different frequencies.

Using the World Health Organization’s (WHO) 2001 descriptions, hearing loss is typically grouped by pure-tone thresholds: mild (20–34 dB HL), moderate (35–49 dB HL), and moderately severe (50–64 dB HL).¹

In general, these categories suggest increasing communication difficulty in noise. Individuals with mild loss may find conversational speech challenging in noisy settings, while those with moderate or moderately severe loss often experience significant difficulty following most speech in such environments.

These categories were later validated by Humes (2019)², who demonstrated measurable changes in communication ability between degrees of loss. However, this classification system still simplifies the complexity of hearing loss, particularly when individuals with similar thresholds perform very differently in speech-in-noise tasks.  In the WHO 2021 report on hearing,³ when discussing the WHO 2001 descriptions, the following thought-provoking statements were made.

• “While audiometric descriptors (e.g. category, pure-tone average) provide a useful summary of an individual’s hearing thresholds, they should not be used as the sole determinant in the assessment of disability or the provision of intervention(s) including hearing aids or cochlear implants.”

• “The ability to detect pure tones using earphones in a quiet environment is not, in itself, a reliable indicator of hearing disability. Audiometric descriptors alone should not be used as the measure of difficulty experienced with communication in background noise, the primary complaint of individuals with hearing loss.”

These statements do not diminish the importance of the pure tone audiogram, which after all is a fundamental part of any audiological assessment. They simply highlight that hearing loss affects individuals in potentially different ways, and it is how an individual perceives their hearing in addition to further clinical findings that is important. For example, when considering the perceived difficulty of a client with a mild loss, as opposed to just focusing on the audiogram, the HCP may suggest a hearing instrument.

Previously this individual might have been counselled regarding better listening techniques and encouraged to return for a check-up in case their hearing gets noticeably worse. This reduced reliance on strict audiometric categories is also reflected in the new NAL-NL3 fitting algorithm, which is being released at the time of writing. NAL-NL3 broadens candidacy for amplification by addressing losses that were previously considered unlikely to benefit.⁴ I look forward to learning more about NAL-NL3 in the coming months.

Focusing on an individual’s perceived difficulty, rather than relying solely on generalized categories, leads naturally to a broader way of thinking about hearing loss: the concept of Aural Diversity.

Introducing the concept of Aural Diversity

The concept of Aural Diversity is that there are many differences in hearing and so it might be better to describe hearing as a wide spectrum instead of a simplified normal/impaired classification system.

Hearing changes frequently throughout life in ways that may be temporary or permanent and so most individuals only have what is considered to be normal hearing, for only a very short part of their lives.⁵  An individual is greatly affected by the cumulative effects of their environment, their experiences and changes in their auditory system due to noise exposure, age, genetics, illness etc. It is these changes in the ability to hear that change our overall perception and further change our preferences too. 

While this might seem obvious to many – that we are all different –  the concept of Aural Diversity emphasizes the importance of an individual’s own personal perception and not just a simple classification system based on the pure tone audiogram and categories of hearing loss. Baguley (2022) points out, however, that the concept of Aural Diversity does not diminish the perspective of the clinician in the care of those with hearing loss.⁶

This concept also resonates strongly in clinical practice. When fine-tuning hearing instruments, the adjustments that best meet a client’s perceived comfort and clarity may fall below REM-based targets for a given input level.

In the past, I may have been concerned about insufficient audibility. Now, with Aural Diversity in mind, I feel more comfortable accepting these adjustments when clients report clear benefit. It reinforces the clinician’s role in tailoring care to each individual’s unique needs.

Where this leaves us as clinicians

In this short blog post I have presented two concepts about hearing loss which in my mind are quite thought provoking.  The first is to move away from a purely audiometric definition of hearing loss and focus on the individual’s own perception of difficulty.

The second is to view the ability to hear as a diverse spectrum with the concept of Aural Diversity based on what is possible from the auditory system while considering experience, preference and individual differences.⁵  

These ways of thinking about hearing loss give us the opportunity to focus on clients purely as individuals without placing them into certain categories based on the audiogram with associated clinical expectations.  I would be interested to hear what you think about this, please feel free to add a comment below.

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References

1. World Health Organization. (2001). International classification of functioning, disability and health. Geneva, Switzerland: WHO.
2. Humes L.E. (2019). The World Health Organization’s hearing-impairment grading system: an evaluation for unaided communication in age-related hearing loss. Int J Audiol;58(1):12–20.
3. World Health Organization. (2021). World report on hearing. Geneva, Switzerland: WHO
4. Hearing Practitioner Australia (2025, March). Groundbreaking NAL-NL3 fitting formula reveals new ways of fitting hearing aids – Hearing Practitioner Australia. Accessed September 24^th 2025
5. Drever, J. L. & Hugill, A. (2022). Aural diversity: General introduction. In Aural Diversity,1-12, Oxford UK: Routledge.
6. Baguley, D. M. (2022). Aural Diversity: A Clinical Perspective. In Aural Diversity, 13-23, Oxford UK: Routledge.