變頻耳聲傳射是當耳蝸放大聲音時產生的一種反向傳遞波。其訊號在相對嘈雜的條件下仍可以快速地被偵測到。近年來，耳機產業有意願採用變頻耳聲傳射作為降噪耳機的附加功能，使他們的產品能夠偵測內耳狀態。然而會面臨一個技術問題：揚聲器會在與變頻耳聲傳射相同的頻率上產生三次方失真，且此種揚聲器失真的強度通常是與變頻耳聲傳射的強度相當。在本篇論文中，我們提出能在僅有單一揚聲器下測量變頻耳聲傳射的策略，我們稱之為「消除策略」。這項策略利用一維沃爾泰拉濾波器消除揚聲器的三次方失真。經過在正常人耳中的測試，結果顯示這項消除策略可以同時復原變頻耳聲傳射訊號的振幅與相位，並使振幅的均方估計誤差自15.5 dB 降低至3.9 dB。

The distortion-product otoacoustic emission (DPOAE) is a backward propagating wave generated inside the cochlea during the wave amplification process. The DPOAE signal can be detected rapidly under relatively noisy conditions. In recent years, the earphone industry demonstrated interest in adopting DPOAE as an add-on feature to make their product ``intelligent'' of inner-ear status. However, a technical challenge remains to be tackled -- the loudspeaker in an earphone generates its own cubic distortion at the same frequency as DPOAE. Unfortunately, the intensity of loudspeaker distortion is typically comparable to that of the DPOAE, if not higher. In this research, we propose a cancellation strategy to enable DPOAE measurement with a single loudspeaker. This strategy utilizes a one-dimensional Volterra filter to remove the cubic distortion from the loudspeaker. Testing on normal-hearing ears shows the cancellation strategy directly recovered both the magnitude and the phase of DPOAE, reducing the magnitude estimation error from 15.5 dB to 3.9 dB in the mean-square sense.

Acknowledgements
摘要
Abstract
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 DistortionProduct Otoacoustic Emission . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Intermodulation Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
1.3.1 Syringe Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
1.3.2 Human Ear Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
1.4 Related Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
2 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.1 Equipments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 The Cancellation Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.1 Linear system estimation by phase controlled exponential sweptsine chirp . . . . . .11
2.2.2 IMD3 cancellation by onedimensional Volterra filtering . . . . . . . . . . . . . . .13
3 Experiments and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.1 Sound Level Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.2 ODVF Coefficients Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.3 Syringe Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.4 Human Ear Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
A.1 Suggestions from the oral defense committees . . . . . . . . . . . . . . . . . . . . .41
A.1.1 冀泰石教授. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
A.1.2 白明憲教授. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
A.1.3 李沛群教授. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
A.1.4 劉奕汶教授. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

[1] D. T. Kemp, “Stimulated acoustic emissions from within the human auditory system,” J. Acoust. Soc. Amer., vol. 64, pp. 1386–1391, 1978.
[2] C. A. Shera and J. J. Guinan, Jr, “Evoked otoacoustic emissions arise by two fundamentally different mechanisms: A taxonomy for mammalian OAEs,” J. Acoust. Soc. Amer., vol. 105, pp. 782–798, 1999.
[3] P. M. Zurek, W. W. Clark, and D. O. Kim, “The behavior of acoustic distortion products in the ear canals of chinchillas with normal or damaged ears,” J. Acoust. Soc. Amer., vol. 72, pp. 774–780, 1982.
[4] B. Lonsbury-Martin and G. Martin, “The clinical utility of distortion-product otoacoustic emissions,” Ear and Hearing, vol. 11, pp. 144–154, April 1990.
[5] F. Harris, B. Lonsbury-Martin, B. Stagner, A. Coats, and G. Martin, “Acoustic distortion products in humans: Systematic changes in amplitude as a function of f2/f1 ratio,” J. Acoust. Soc. Amer., vol. 85, no. 1, pp. 220–229, 1989.
[6] L. J. Kanis and E. de Boer, “Two-tone suppression in a locally active nonlinear model of the cochlea,” J. Acoust. Soc. Amer., vol. 96, pp. 2156–2165, 1994.
[7] S. E. Barker, M. M. Lesperance, and P. R. Kileny, “Outcome of newborn hearing screening by ABR compared with four different DPOAE pass criteria,” Amer. J. Audiology, vol. 9, no. 2, pp. 142–148, 2000.
[8] C. A. Sanford, D. H. Keefe, Y.W. Liu, D. Fitzpatrick, R. W. McCreery, D. E. Lewis, and M. P. Gorga, “Sound-conduction effects on DPOAE screening outcomes in newborn infants: Test performance of wideband acoustic transfer functions and 1-khz tympanometry,” Ear and Hearing, vol. 30, no. 6, pp. 635–652, 2009.
[9] D. J. Brown and W. P. Gibson, “On the differential diagnosis of Ménière’s disease using low-frequency acoustic biasing of the 2f1–f2 DPOAE,” Hear. Res., vol. 282, no. 12, pp. 119–127, 2011.
[10] Y. Shiomi, J. Tsuji, Y. Naito, N. Fujiki, and N. Yamamoto, “Characteristics of DPOAE audiogram in tinnitus patients,” Hear. Res., vol. 108, no. 1, pp. 83–88, 1997.
[11] A. Job and J.-B. Nottet, “DPOAEs in young normalhearing subjects with histories of otitis media: Evidence of subclinical impairments,” Hear. Res., vol. 167, no. 1, pp. 28–32, 2002.
[12] Y.-W. Liu and S. T. Neely, “distortion-product emissions from a cochlear model with nonlinear mechanoelectrical transduction in outer hair cells,” J. Acoust. Soc. Amer., vol. 127, pp. 2420–2432, 2010.
[13] M. L. Whitehead, B. B. Stagner, B. L. Lonsbury-Martin, and G. K. Martin, “Measurement of otoacoustic emissions for hearing assessment,” IEEE Engineering in Medicine and Biology Magazine, vol. 13, pp. 210–226, April/May 1994.
[14] H. M. Moir, J. C. Jackson, and J. F. C. Windmill, “No evidence for DPOAEs in the mechanical motion of the locust tympanum,” J. Experimental Biol., vol. 214, pp. 3165–3172, 2011.
[15] H. M. Moir, J. C. Jackson, and J. F. C. Windmill, “Response to ‘Measurement of sensitive distortion-product otoacoustic emissions in insect tympanal organs’,” J. Experimental Biol., vol. 215, pp. 567–567, 02 2012.
[16] M. van der Heijden and P. X. Joris, “Cochlear phase and amplitude retrieved from the auditory nerve at arbitrary frequencies,” J. Neurosci., vol. 23, no. 27, pp. 9194–9198, 2003.
[17] L. J. Campbell and K. D. Slater, Personalization of auditory stimulus. United States: 9497530B1, Nov. 2016.
[18] M. V. der Aerschot, D. W. Swanepoel, F. Mahomed-Asmail, H. C. Myburgh, and R. H. Eikelboom, “Affordable headphones for accessible screening audiometry: An evaluation of the Sennheiser HD202 II supra-aural headphone,” Int. J. Audiology, vol. 55, no. 11, pp. 616–622, 2016.
[19] R. Kalluri and C. A. Shera, “Distortion-product source unmixing: A test of the two-mechanism model for DPOAE generation,” J. Acoust. Soc. Amer.,
vol. 109, no. 2, pp. 622–637, 2001.
[20] L. A. Shaffer, R. H. Withnell, S. Dhar, D. J. Lilly, S. S. Goodman, and K. M. Harmon, “Sources and mechanisms of DPOAE generation: Implications for the prediction of auditory sensitivity,” Ear and Hearing, vol. 24, no. 5, pp. 367–379, 2003.
[21] G. Zweig and C. A. Shera, “The origin of periodicity in the spectrum of evoked otoacoustic emissions,” J. Acoust. Soc. Amer., vol. 98, pp. 2018–2047, 1995.
[22] A. Vetesník, D. Turcanu, E. Dalhoff, and A. W. Gummer, “Extraction of sources of distortion product otoacoustic emissions by onset-decomposition,” Hear. Res., vol. 256, no. 1–2, pp. 21–38, 2009.
[23] T.-C. Liu, Y.-W. Liu, and H.-T. Wu, “Denoising clickevoked otoacoustic emission signals by optimal shrinkage,” J. Acoust. Soc. Amer., vol. 149, pp. 2659–2670, 2021.
[24] A. V. Oppenheim and R. W. Schafer, Discrete-time Signal Processing. Upper Saddle River, New Jersey: Pearson, 3rd ed., 2010.
[25] K. Vetter and S. di Rosario, “Expochirptoolbox: a Pure Data implementation of ESS impulse response measurement,” in Proc. Pure Data Convention, 2011.
[26] C. Lesiak and A. Krener, “The existence and uniqueness of volterra series for nonlinear systems,” IEEE Trans. Automatic Control, vol. 23, no. 6, pp. 1090–1095, 1978.
[27] Y. Mu, P. Ji, W. Ji, M. Wu, and J. Yang, “Modeling and compensation for the distortion of parametric loudspeakers using a one-dimension
volterra filter,” IEEE/ACM Trans. Audio, Speech, and Language Processing, vol. 22, no. 12, pp. 2169–2181, 2014.
[28] B. Widrow and S. Stearns, Adaptive Signal Processing. Englewood Cliffs, NJ: PrenticeHall, 1985.
[29] B. Venema, N. Blanik, V. Blazek, H. Gehring, A. Opp, and S. Leonhardt, “Advances in reflective oxygen saturation monitoring with a novel in-ear
sensor system: Results of a human hypoxia study,” IEEE Trans. Biomed. Engineering, vol. 59, no. 7, pp. 2003–2010, 2012.
[30] V. Goverdovsky, D. Looney, P. Kidmose, and D. P. Mandic, “In-ear EEG from viscoelastic generic earpieces: Robust and unobtrusive 24/7 monitoring,” IEEE Sensors Journal, vol. 16, no. 1, pp. 271–277, 2016.