Impact of adding artificially generated alert sound to hybrid electric vehicles on their detectability by pedestrians who are blind.

A repeated-measures design with block randomization was used for the study, in which 14 adults with visual impairments attempted to detect three different vehicles: a hybrid electric vehicle (HEV) with an artificially generated sound (Vehicle Sound for Pedestrians [VSP]), an HEV without the VSP, and a comparable internal combustion engine (ICE) vehicle. The VSP vehicle (mean +/- standard deviation [SD] = 38.3 +/- 14.8 m) was detected at a significantly farther distance than the HEV (mean +/- SD = 27.5 +/- 11.5 m), t = 4.823, p < 0.001, but no significant difference existed between the VSP and ICE vehicles (mean +/- SD = 34.5 +/- 14.3 m), t = 1.787, p = 0.10. Despite the overall sound level difference between the two test sites (parking lot = 48.7 dBA, roadway = 55.1 dBA), no significant difference in detection distance between the test sites was observed, F(1, 13) = 0.025, p = 0.88. No significant interaction was found between the vehicle type and test site, F(1.31, 16.98) = 0.272, p = 0.67. The findings of the study may help us understand how adding an artificially generated sound to an HEV could affect some of the orientation and mobility tasks performed by blind pedestrians.

[1]  G. Keppel.  Design and analysis: A researcher's handbook, 3rd ed. , 1991 .

[2]  B. Moore.  An introduction to the psychology of hearing, 3rd ed. , 1989 .

[3]  H. Bastian.  Sensation and Perception.—I , 1869, Nature.

[4]  R. Thouless.  Experimental Psychology , 1939, Nature.

[5]  D. M. Green,et al.  Masking produced by spectral uncertainty with multicomponent maskers , 1987, Perception & psychophysics.

[6]  James Berline.  Orientation and Mobility: Techniques for Independence , 2011 .

[7]  Paul Nelson,et al.  Transportation Noise Reference Book , 1987 .

[8]  Jacob Cohen.  Statistical Power Analysis for the Behavioral Sciences , 1969, The SAGE Encyclopedia of Research Design.

[9]  J. P. Morgan,et al.  Design and Analysis: A Researcher's Handbook , 2005, Technometrics.

[10]  Koorosh Naghshineh,et al.  A Pilot Study of Pedestrians with Visual Impairments Detecting Traffic Gaps and Surges Containing Hybrid Vehicles. , 2011, Transportation research. Part F, Traffic psychology and behaviour.

[11]  Lawrence D. Rosenblum,et al.  Are hybrid cars too quiet , 2009 .

[12]  S. L. Grow,et al.  Orientation and Mobility: Techniques for Independence , 2011 .

[13]  W. Jacobson.  The Art and Science of Teaching Orientation and Mobility to Persons With Visual Impairments , 1993 .

[14]  G. Gescheider.  Psychophysics: The Fundamentals , 1997 .

[15]  R H Margolis,et al.  Detection of tones in band-reject noise. , 1981, Journal of speech and hearing research.

[16]  J Lelong.  VEHICLE NOISE EMISSION: EVALUATION OF TYRE/ROAD AND MOTOR-NOISE CONTRIBUTIONS , 1999 .

[17]  E. Owens,et al.  An Introduction to the Psychology of Hearing , 1997 .

[18]  William Allen.  Orientation and mobility teaching manual , 1997 .

[19]  Alan R. Palmer,et al.  Chapter 3 – Neural Signal Processing , 1995 .

[20]  Robert Wall Emerson,et al.  Modern Roundabouts: Access by Pedestrians who are Blind , 2005 .

[21]  Donna L. Hudson,et al.  Neural Signal Processing , 2005 .

[22]  Deborah Kent.  Book Review: Modular Instruction for Independent Travel for Students who are Blind or Visually Impaired: Preschool through High School , 2000 .

[23]  Koorosh Naghshineh,et al.  The Impact of Hybrid Vehicles on Street Crossings. , 2006 .

[24]  D.A. Guth,et al.  Tests of Blind Pedestrians’ Use of Traffic Sounds for Street-crossing Alignment , 1989 .

[25]  A. Everett,et al.  Orientation and Mobility Techniques: A Guide for the Practitioner , 1976 .

[26]  D. M. Green,et al.  Signal detection theory and psychophysics , 1966 .

[27]  Dona Sauerburger,et al.  Detecting Approaching Vehicles at Streets with No Traffic Control , 2008, Journal of visual impairment & blindness.

[28]  Perception of Spectral Changes in Multi-tone Complexes , 1991, The Quarterly journal of experimental psychology. A, Human experimental psychology.

[29]  Dot Hs.  Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles , 2009 .

[30]  Neil A. Macmillan,et al.  Detection theory: A user's guide, 2nd ed. , 2005 .

[31]  Refaat Hanna.  Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles , 2009 .

[32]  Edgar Erdfelder,et al.  GPOWER: A general power analysis program , 1996 .

[33]  M. Lévesque.  Perception , 1986, The Yale Journal of Biology and Medicine.

[34]  Neil A. Macmillan,et al.  Detection Theory: A User's Guide , 1991 .

[35]  W Jesteadt,et al.  Intensity discrimination in the presence of random-frequency, multicomponent maskers and broadband noise. , 1996, The Journal of the Acoustical Society of America.

[36]  D. L. Neff,et al.  Effective properties of multicomponent simultaneous maskers under conditions of uncertainty. , 1988, The Journal of the Acoustical Society of America.

[37]  D. Sauerburger.  Safety Awareness for Crossing Streets with No Traffic Control , 1995 .

[38]  George A. Gescheider,et al.  Psychophysics: The Fundamentals , 1997 .