Contents: 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001

2007, 17

Milind N. Kunchur

Audibility of temporal smearing and time misalignment of acoustic signals

language: English

received 19.07.2007, published 29.08.2007

Download article (PDF, 430 kb, ZIP), use browser command "Save Target As..."
To read this document you need Adobe Acrobat © Reader software, which is simple to use and available at no cost. Use version 4.0 or higher. You can download software from Adobe site (

Erratum 08.04.2008 (PDF, 20 kb, ZIP)


Misalignment in timing between drivers in a speaker system and temporal smearing of signals in components and cables has long been alleged to cause degradation of fidelity in audio reproduction. It has also been noted that listeners prefer higher sampling rates (e.g., 96 kHz) than the 44.1 kHz of the digital compact disk, even though the 22 kHz Nyquist frequency of the latter already exceeds the nominal single-tone high-frequency hearing limit of about 18 kHz (i.e., an angular frequency limit of 113,000 rad/s). These qualitative and anecdotal observations point to the possibility that human hearing may be sensitive to temporal errors, that are shorter than the reciprocal of the limiting angular frequency (about 9 microseconds), thus necessitating bandwidths in audio equipment that are much higher than hearing limit frequency in order to preserve fidelity. The blind trials of the present work provide quantitative proof of this by assessing the discernability of time misalignment between signals from spatially displaced speakers. The experiment found a displacement threshold of about 2 mm corresponding to a delay discrimination of about 6 microseconds.

Keywords: time, temporal, align, alignment, smearing, resolution

18 pages, 6 figures

Сitation: Milind N. Kunchur. Audibility of temporal smearing and time misalignment of acoustic signals. Electronic Journal “Technical Acoustics”,, 2007, 17.


[1] H. R. E. van Maanen. Temporal decay: a useful tool for the characterization of resolution of audio systems. AES Preprint 3480 (C1–9). Presented at the 94-th convention of the Audio Engineering Society in Berlin, 1993.
[2] W. Woszczyk. Physical and Perceptual Considerations for High-Resolution Audio. Audio Engineering Society Convention Paper 5931. Presented at the 115-th Convention 2003 October 10–13 New York, New York, 2003.
[3] N. Thiele. Phase considerations in Loudspeaker Systems. Audio Engineering Society Convention Paper 5307. Presented at the 110th Convention 2001 May 12–15 Amsterdam, The Netherlands, 2001.
[4] J. R. Stuart. Coding for high-resolution audio systems. J. Audio Eng. Soc., vol. 52, pp. 117–144, 2004.
[5] M. R. Schroeder. Models of hearing. Proc. of the IEEE, vol. 63, pp. 1332, 1975.
[6] W. M. Hartmann, Signals, sound, and sensation (Modern Acoustics and Signal Processing). AIP Press, 1996.
[7] K. W. Berger. Some factors in the recognition of timbre. J. Acoust. Soc. Am., vol. 36, 1988, 1963.
[8] D. Oertel, R. Bal, S. M. Gardner, P. H. Smith, and P. X. Joris. Detection of synchrony in the activity of auditory nerve fibers by octous cells of the mammalian cochlear nucleus. Proc. Nat. Acad. Sci., vol. 97, pp. 11773–11779, 2000.
[9] N. L. Golding, D. Robertson, D. Oertel. Recordings from slices indicate that octopus cells of the cochlear nucleus detect coincident firing of auditory nerve fibers with temporal precision. J. Neurosci., vol. 15, pp. 3138–3153, 1995.
[10] M. J. Ferragamo and D. Oertel. Shaping of synaptic responses and action potentials in octopus cells. Assoc. Res. Otolaryngol., vol. 21, pp. 96, 1998.
[11] D. H. Johnson. The response of single auditory-nerve fibers in the cat to single tones: synchrony and average discharge rate. Ph.D. thesis. Department of Electrical Engineering. MIT. Cambridge, MA, 1974.
[12] S. A. Shamma, N. Shen, G. Preetham. Stereausis: Binaural processing without neural delays. J. Acoust. Soc. Am., vol. 86, pp. 989–1006, 1989.
[13] I. Pollack. Submicrosecond auditory jitter discrimination thresholds. J. Acoust. Soc. Am., vol. 45, pp. 1059–1059, 1969.
[14] I. Pollack. Spectral basis of auditory jitter discrimination. J. Acoust. Soc. Am., vol. 50, pp. 555, 1971.
[15] B. H. Deatherage. L. A. Jeffress, and H. C. Blodgett. A note on the audibility of intense ultrasound. J. Acoust. Soc. Am., vol. 26, pp. 582, 1954.
[16] F. J. Corso. Bone conduction thresholds for sonic and ultrasonic frequencies. J. Acoust. Soc. Am., vol. 35, pp. 1738–1743, 1963.
[17] M. L. Lenhardt, R. Skellett, P. Wang, and A. M. Clarke. Human ultrasonic speech perception. Science, vol. 253, pp. 82–85, 1991.
[18] M. L. Lenhardt. Human ultrasonic hearing. Hearing Rev., vol. 5, pp. 50–52, 1998.
[19] S. Fujioka. Bone Conduction Hearing for Ultrasound. Trans. Tech. Com. Physio. Acoust. Soc. Japan. H-97-4, 1997.
[20] H. E. von Gierke. Subharmonics generated in human and animal ears by intense sound. J. Acoust. Soc. Am., vol. 22, pp. 675, 1950.
[21] K. Ashihara, K. Kurukata, T. Mizunami, and K. Matsushita. Hearing threshold for pure tones above 20 kHz. Acoust. Sci. & Tech., vol. 27, pp. 12–19, 2006.
[22] T. Oohashi, E. Nishina, N. Kawai, Y. Fuwamoto, and H. Imai. High-frequency sound above the audible range affects brain electric activity and sound perception. J. Audio Eng. Soc. (Abstracts), vol. 39, pp. 1010, 1991.
[23] S. Yoshikawa, S. Noge, M. Ohsu, S. Toyama, H. Yanagawa, T. Yamamoto. Sound-quality evaluation of 96-kHz sampling digital audio. J. Audio Eng. Soc. (Abstracts), vol. 43, pp. 1095, 1995.
[24] M. J Shailer and B. C. J. Moore. Gap Detection and the Auditory Filter: Phase Effects Using Sinusoidal Stimuli. J. Acoust. Soc. Am., vol. 81, pp. 1110–1117, 1987.
[25] C. Formby, M. Gerber, L. Sherlock, and L. Magder. Evidence for an across-frequency, between-channel process in asymptotic monaural temporal gap detection. J. Acoust. Soc. Am., vol. 103. pp. 3554–3560, 1998.
[26] B. C. J. Moore. An Introduction to the Psychology of Hearing. 5-th ed., Academic Press, 2003.
[27] R. Plomp. Rate of decay of auditory sensation. J. Acoust. Soc. Am., vol. 36, pp. 277–282, 1964.
[28] M. J. Penner. Detection of temporal gaps in noise as a measure of the decay of auditory sensation. J. Acoust. Soc. Am., vol. 61, pp. 552–557, 1977.
[29] D. A. Eddins, J. W. Hall, and J. H. Grose. Detection of temporal gaps as a function of frequency region and absolute bandwidth. J. Acoust. Soc. Am., vol. 91, pp. 1069–1077, 1992.
[30] D. P. Allen, T. M. Virag, and J. R. Ison. Humans detect gaps in broadband noise according to effective gap duration without additional cues from abrupt envelope changes. J. Acoust. Soc. Am., vol. 112, pp. 2967–2974, 2002.
[31] B. Leshowitz. Measurement of the two-click threshold. J. Acoust. Soc. Am., vol. 49, pp. 462–466, 1971.
[32] D. Ronken. Monaural detection of a phase difference between clicks. J. Acoust. Soc. Am., vol. 47, pp. 1091–1099, 1970.
[33] G. B. Henning and H. Gaskell. Monaural phase sensitivity with Ronken’s paradigm. J. Acoust. Soc. Am., vol. 70, pp. 1669–1673, 1981.
[34] K. Krumbholz, R. D. Patterson, A. Bobbe, and H. Fastl. Microsecond temporal resolution in monaural hearing without spectral cues. J. Acoust. Soc. Am., vol. 113, 2790–2800, 2003.
[35] K. Ashihara, and S. Kiryu. Influence of expanded frequency band of signals on non-linear characteristics of loudspeakers. Nippon Onkyo Gakkai Shi (J. Acoust. Soc. Jap.), vol. 56, pp. 549–555, 2000.
[36] International Standards Organization minimum audible field (MAF) standard: ISO 389-7, 1996.
[37] K. Kurukata, T. Mizunami, K. Matsushita, and K. Ashihara. Statistical distribution of normal hearing thresholds under free-field listening conditions. Acoust. Sci. & Tech., vol. 26, pp. 440–446, 2005.
[38] P. Rogowski, A. Rakowski, and A. Jaroszewski. Specific Hearing Loss in Young Percussion and Brass Wind Players due to Music Noise Exposures. The 8th International Congress on Sound and Vibration. Hong Kong, China. 2–6 July, 2001.
[39] J. Boyk. There’s life above 20 kilohertz! A survey of musical instrument spectra to 102.4 kHz. boyk/spectra/spectra.htm. Copyright ©1992, 1997 James Boyk. Music Lab. California Institute of Technology.
[40] W. Jesteadt. C. C. Wier, and D. M. Green, Intensity discrimination as a function of frequency and sensation level. J. Acoust. Soc. Am., vol. 61, pp. 169–177, 1977.
[41] R. Plomp and H. J. M. Steeneken. The effect of phase on the timbre of complex tones. J. Acoust. Soc. Am., vol. 46, pp. 409–421, 1969.


Milind N. Kunchur received his Ph.D. degree in Physics from Rutgers University in 1988. He is currently a Professor in the Department of Physics and Astronomy at the University of South Carolina, before which he held appointments at Oak Ridge National Laboratory and at the Wright Patterson Air Force Base. Professor Kunchur has taught a course on Musical Acoustics for many years. He is interested in understanding the human hearing mechanism and how its limits relate to fidelity in sound reproduction. He is a member of APS, AES, ASA, and SCAS professional societies. The web site: contains further information and a list of publications.

e-mail: kunchur(at)