İşitmeAtölyesiAt a glance
Disruption of neural synchrony due to a problem at the inner hair cells, ribbon synapses or auditory nerve, while outer hair cells are preserved.
A mismatch between pure-tone thresholds and speech understanding; marked difficulty understanding speech, especially in noise.
Not an emergency; but early diagnosis is critical for language development in infants.
Individualised plan: FM/remote microphone, hearing aid in selected cases, cochlear implant in suitable cases.
Medical disclaimer. This content is for informational purposes only and does not replace a physician’s examination, diagnosis or treatment; it should not be used as medical advice. For your complaints or personal situation, always consult an ear, nose and throat physician and an audiologist.
If your baby’s hearing screening flagged a problem (especially with a neonatal intensive care history) or your child gives the impression of “hearing but not understanding” or “sometimes hears, sometimes doesn’t,” consult an audiologist. Screening with OAE alone can miss ANSD; an ABR-based assessment is needed.
Definition and epidemiology
Auditory neuropathy spectrum disorder (ANSD) is a picture in which neural synchrony is disrupted by a problem at the inner hair cells, ribbon synapses or auditory nerve, while outer hair-cell function is preserved (Starr et al., 1996).
When the problem is at the synaptic level it is called “auditory synaptopathy,” and at the nerve level “auditory neuropathy.” In both, the core problem is not hearing the sound but transmitting it in a temporally well-ordered way.
ANSD is more common in infants with a neonatal intensive care history and makes up a small but important portion of congenital hearing losses; this shows that OAE alone is insufficient in screening (Rance & Starr, 2015).
Symptoms and signs
The most typical symptom is a mismatch between pure-tone thresholds and speech understanding: the person can hear sounds but has marked difficulty understanding speech, especially in noise.
Hearing thresholds can range from normal to profound and, in some cases, fluctuate. In some genetic forms hearing can temporarily worsen during febrile illness and improve when the fever falls.
In children, delayed speech-language development and the impression of “sometimes hears, sometimes doesn’t” are common; this can delay diagnosis.
Causes and risk factors
The aetiology can be genetic, perinatal or idiopathic. The OTOF gene (otoferlin) affects synaptic release, leading to a pre-synaptic form; the OPA1 gene leads to a post-synaptic form at the auditory-nerve level. PJVK (pejvakin) is associated with heightened noise sensitivity.
Non-genetic risk factors include high bilirubin (jaundice) in the neonatal period, prematurity and hypoxia; these factors can impair the maturation or function of the auditory pathways.
Establishing the genotype-phenotype relationship is guiding, especially for predicting cochlear-implant outcomes.
Audiological and clinical assessment
The “cross-check” principle is essential in diagnosing ANSD; a normal result on a single test does not exclude the diagnosis. In particular, screening with OAE alone can miss ANSD.
- OAE: usually present/normal (outer hair cells preserved).
- Cochlear microphonic (CM): present and normal; reflects receptor function.
- ABR: absent or markedly abnormal; shows the neural dyssynchrony (the key to diagnosis).
- Acoustic reflexes: often absent or with very high thresholds.
- ECochG and electrical tests (eABR/eCAP): used to localise the lesion and in pre-cochlear-implant assessment.
For this reason it is important that neonatal hearing screening in at-risk babies be ABR-based.
| Test | What it measures | Typical ANSD finding |
|---|---|---|
| OAE | Outer hair-cell function | Present / normal |
| Cochlear microphonic (CM) | Receptor (hair-cell) response | Present / normal |
| ABR | Neural synchrony | Absent / markedly abnormal |
| Acoustic reflex | Brainstem reflex pathway | Absent / very high threshold |
| Speech discrimination | Functional hearing | Worse than expected for thresholds |
Treatment and audiological rehabilitation
Management is individualised; decisions are based on the child’s speech-language development and functional hearing rather than on pure-tone thresholds alone.
FM/remote microphone systems support communication, especially in school-age children, by increasing the signal-to-noise ratio in noise. Some patients benefit from a hearing aid.
A cochlear implant is an effective option, especially in cases with poor speech discrimination. Outcomes are variable in nerve-level involvement; in synaptic-level forms (e.g., OTOF), implant outcomes are usually very good (Santarelli et al., 2015). In OTOF-related forms, gene therapy is a promising research area; early-phase studies have reported meaningful hearing gains. These treatments are still at the research/early-application stage and are mutation-specific (Lv et al., 2024).
Impact on quality of life and advice
The unpredictability of hearing can cause anxiety in the child and family and fluctuation in school success. Early, correct diagnosis is critical for timely rehabilitation.
The use of an FM system in noisy environments, classroom acoustic arrangements and regular follow-up are recommended. Counselling for the family, setting realistic expectations and communication support are important parts of the process.
If you used this review, you can cite it as follows (APA 7):
İşitme Atölyesi. (2026). Auditory Neuropathy Spectrum Disorder (ANSD). Hearing & Balance Health Guide. https://www.isitmeatolyesi.com/en/guncel-haberler/categories/isitme-sagligi-rehberi/isitsel-noropati-spektrum-bozuklugu/Permanent link: isitmeatolyesi.com/en/guncel-haberler/categories/isitme-sagligi-rehberi/isitsel-noropati-spektrum-bozuklugu/ · Last reviewed: July 2026 · License: CC BY-NC-ND 4.0
References
- Lv, J., Wang, H., Cheng, X., et al. (2024). AAV1-hOTOF gene therapy for autosomal recessive deafness 9: A single-arm trial. The Lancet, 403(10441), 2317-2325.
- Rance, G., & Starr, A. (2015). Pathophysiological mechanisms and functional hearing consequences of auditory neuropathy. Brain, 138(11), 3141-3158.
- Santarelli, R., del Castillo, I., & Cama, E. (2015). Auditory neuropathy: From molecular mechanisms to clinical management. Otology & Neurotology, 36(3), 366-378.
- Starr, A., Picton, T. W., Sininger, Y., Hood, L. J., & Berlin, C. I. (1996). Auditory neuropathy. Brain, 119(3), 741-753.
Frequently asked questions
My child hears sounds but doesn’t understand; how?
In auditory neuropathy the inner ear can perceive sounds, but these sounds are not transmitted to the brain with regular timing via the nerve. So the child notices that a sound is present but struggles to make sense of speech, especially in noise. This condition can be recognised and supported with appropriate methods.
Does a ‘pass’ on an OAE test mean my child hears normally?
Not necessarily. OAE measures only part of the inner ear; in auditory neuropathy this test can be normal. Therefore, especially in babies with an intensive-care history, an ABR test should also be done so the diagnosis is not missed.
Why do febrile illnesses affect hearing?
In some genetic forms the proteins that provide hearing are heat-sensitive; when body temperature rises, hearing can temporarily decrease markedly. Hearing returning to its former state when the fever falls is a characteristic feature of these forms.
Does a cochlear implant work in every child with ANSD?
A cochlear implant gives very good results in many children, especially when the problem is at the synaptic level. However, outcomes are variable when the auditory nerve is severely affected. That is why a detailed electrophysiological and imaging assessment is done before the implant decision.
Is gene therapy possible now?
In OTOF-related forms, early-phase studies of gene therapy have shown promising results. However, these treatments are still at the research/early-application stage, apply only to certain gene mutations, and cannot be given to every patient.
Scales that can be used to monitor language development and functional listening in children: