Handbook for Sound Engineers

Psychoacoustics 61

When a sound source is very far, because the air
absorbs high-frequencies more than the low-frequen-
cies, the perceived sound would contain more
low-frequency energy, with a darker timbre. This is why
thunder far away is just rumble whereas thunder nearby
has a crack to it. However, this is a very weak effect^58
and therefore is relatively insignificant for events
nearby, which is mostly the case in everyday life.
A more compelling cue for replicating and

perceiving distance is adjusting the ratio of the direct to

reverberant sound. In real spaces, a sound nearby will

not only be louder but also will have a relatively high

direct-to-reverberant ratio. As the sound moves away, it

gets quieter, and the direct-to-reverberant ratio reduces

until critical distance is reached. At critical distance the

direct and reverberant levels are equal. Moving a sound

source beyond critical distance will not result in an

increased sense of distance.

Further Reading

Textbooks on psychoacoustics and auditory physiology are available for various audiences. One might find some of

the following books to be helpful:

B. C. J. Moore, “An introduction to the psychology of hearing,” 5th Ed., Academic Press, London (2003).

C. J. Plack, “The sense of hearing,” Lawrence Erlbaum Associates, NJ (2005).

J. O. Pickles, “An introduction to the physiology of hearing,” 2nd Ed., Academic Press, London (1988).

J. D. Durrant and J. H. Lovrinic, “Bases of hearing science,” 3rd Ed., Williams and Wilkins, Baltimore, MD (1995).

W. M. Hartmann, “Signals, sound and sensation,” 5th Ed., Springer, NY (2004).

J. Blauert, “Spatial hearing: The psychophysics of human sound localization,” MIT Press, Cambridge (1997).

H. Fastl and E. Zwicker, “Psychoacoustics: facts and models,” 3rd Ed., Springer, NY (2006).

W. Yost, “Fundamentals of hearing: An introduction,” 5th Ed., Academic Press, NY (2006).

References

1. Douglas Jones, personal communications (2007).


2. J. C. Middlebrooks, “Virtual localization improved by scaling nonindividualized external-ear transfer functions
   in frequency,” J. Acoust. Soc. Am., 106 , 1493-1510 (1999).


3. H. Haas, “Über den Einfluss eines Einfachechos an die Hörsamkeit von Sprache, Acustica,” 1 , 49-58 (1951).


4. F. M. Weiner and D. A. Ross, “Pressure distribution in the auditory canal in a progressive sound field,” J. Acoust.
   Soc. Am., 18 , 401-408 (1946).


5. E. A. G. Shaw, “The external ear,” Handbook of sensory physiology, ed. W. D. Keidel and W. D. Neff, vol. 5/1,
   pp 455-490, Springer, Berlin (1974).


6. J. D. Durrant and J. H. Loverinic, “Bases of hearing science,” 3rd Ed., p164, Williams and Wilkins, Baltimore,
   MD (1995).


7. V. Nedzelnitsky, “Sound pressures in the basal turn of the cat cochlea,” J. Acoust. Soc. Am., 68 , 1676-1689
   (1980).


8. J. O. Pickles, “An introduction to the physiology of hearing,” 2nd Ed., pp16-20, Academic Press, London (1988).


9. M. Portmann and G. Lacher, “Present management of the reconstruction of the middle ear,” Clinical Otolaryngol-
   ogy, 12 (5), 389–395 (1987).


10. US Patent, “Communication device using bone conduction,” US Patent 6885753.


11. P. W. Carmel and A. Starr, “Acoustic and non-acoustic factors modifying middle-ear muscle activity in waking
    cats,” J. Neurophysiol, 26 , 598-616 (1963).


12. J. D. Durrant and J. H. Loverinic, “Bases of hearing science,” 3rd Ed., p172, Williams and Wilkins, Baltimore,
    MD (1995).


13. G. von Békésy, “Experiments in hearing,” McGraw-Hill, NY (1960).