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An off-the-shelf otoacoustic-emission probe for hearing screening via a smartphone


Otoacoustic emissions (OAEs) provide information about the function of the outer hair cells of the cochlea. In high-income countries, infants undergo OAE tests as part of the screening protocols for hearing. However, the cost of the necessary equipment hinders early screening for hearing in low- and middle-income countries, which disproportionately bear the brunt of disabling hearing loss. Here we report the design and clinical testing of a low-cost probe for OAEs. The device, which has a material cost of approximately US$10, uses an off-the-shelf microphone and off-the-shelf earphones connected to a smartphone through a headphone jack. It sends two pure tones through each of the headphone’s earbuds and algorithmically detects the distortion-product OAEs generated by the cochlea and recorded via the microphone. In a clinical study involving 201 paediatric ears across three healthcare sites, the device detected hearing loss with 100% sensitivity and 88.9% specificity, comparable to the performance of a commercial device. Low-cost devices for OAE testing may aid the early detection of hearing loss in resource-constrained settings.

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Fig. 1: Overview of the earphone-based OAE probe system.
Fig. 2: Performance of the clinical study.
Fig. 3: Device performance in infant ears under 6 months of age.
Fig. 4: Audiograms of patient ears.
Fig. 5: Device performance in patient ears with SNHL.
Fig. 6: Benchmark testing across multiple smartphones.
Fig. 7: Benchmark testing of hardware distortion.

Data availability

All data supporting the findings from this study are available within the article and its Supplementary Information. The dataset used to generate the results for this study is available at and (ref. 48). Source data are provided with this paper.

Code availability

The custom code used in this study is available at and (ref. 48).


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We thank our participants and their families at Seattle Children’s Hospital. We thank K. Sie, D. Horn and H. Ou at the Seattle Children’s Hospital and Research Institute for permitting us to recruit patients from their clinics. We thank S. Norton for her critical and important feedback on the manuscript and methods. N.A. discloses support for the research described in this study from the National Institute on Deafness and Other Communication Disorders award T32DC000018. R.B. and S.G. disclose support for the research described in this study from the Washington Research Foundation, Seattle Children’s Research Institute, Research Integration Hub. S.G. discloses support for the research described in this study from the Moore Inventor Fellow award #10617.

Author information

Authors and Affiliations



All authors designed the experiments and interpreted the results. J.C. and S.G. wrote the manuscript, and N.A., A.M., L.R.M., E.G. and R.B. edited the manuscript. J.C., N.A. and A.M. conducted the experiments and performed the analysis, under technical supervision by S.G. and J.C.; A.N. and S.G. designed the algorithms. J.C. and S.G. conceptualized the study.

Corresponding authors

Correspondence to Justin Chan, Randall Bly or Shyamnath Gollakota.

Ethics declarations

Competing interests

S.G., J.C. and R.B. are co-founders of Wavely Diagnostics, Inc. S.G. is a co-founder of Jeeva Wireless, Inc. and Sound Life Sciences. R.B. is a co-founder of EigenHealth, Inc. R.B. is a consultant and stockholder of Spiway, LLC. The other authors declare no competing interests.

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Supplementary data

Source data for Supplementary Figs. 2, 3 and 8.

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Source data for Figs. 2–7.

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Chan, J., Ali, N., Najafi, A. et al. An off-the-shelf otoacoustic-emission probe for hearing screening via a smartphone. Nat. Biomed. Eng 6, 1203–1213 (2022).

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