Free response to auditory signal detection, signal fading rate on energy band detector for electric ear model, and brightness adaptation research project

Jeffress, L. A.

English

NASA Technical Reports Server

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Semiannual Report, Contract Nonr 3 5 B ( O k )  ( U )  
1 December 1'365 through 31 ;day 1966 
Office of Grants and Research Contracts, 
National Aeronautics and Space Administration 
and 
Eighth Quarterly Status  Report 
NASA Number R-18-09-030-017 ( U )  
1 March 1966 through 31 May 1966 
Supported by Fund Transfer R - 1 3  from 
27 June 1966 Copy No. & 
Prepared by L. A. J e f f r e s s  
%/A. J k H  r e s s  
Project Supervisor 
Approved by: Approved by : 
@-/{@A 
R. H. Wallace 
Head, Acoustics Division 
C .  M. McKinney 
Direct or 
DEFENSE RESEARCH LABORATORY 
THE UNIVERSITY OF TEXAS 
AUSTIN, TEXAS 78712 
https://ntrs.nasa.gov/search.jsp?R=19660022851 2020-03-16T21:12:53+00:00Z
27 June 1966 
LAJ:dv 
Semiannual Report for Contract Nonr-3579(04) 
f o r  the period of  1 December 1965 through 31 May 1966 
Supported by Fund Transfer R-129  from Office o f  Grants and Research Contracts 
National Aeronautics and Space Administration 
and 
Eighth Quarterly S ta tus  Report for NASA number R-129-09-030-017 
f o r  the  period 1 March 1966 through 31 May 1966 
by 
L loyd  A. J e f f r e s s  
I. STATUS OF PROPOSED PROBLEM 
A. Method of Free Response 
7 C .  S.. Watson and T .  L. Nichols) 
A s  an outgrowth of the vigilance s tudies  completed ea r l i e r ,  a modification 
of Egan's method o f  f r ee  response has been developed. Results using the 
method w i l l  be reported at the  June meeting of the Acoustical Society of 
America, and the work i s  being prepared f o r  publication and f o r  issuance a s  a 
DRL Acoustical Report. The abstract  o f  the  paper t o  be presented a t  the June 
meeting i s  included i n  the appendix. 
The data  col lect ion phase of an experiment concerning the  e f f e c t s  of 
adaptation on the  brightness of flashed incremental and decremental s t imul i  
i s  now completed. 
estimates of brightness were obtained from 25 subjects  who viewed b r i e f  
(300 msec) f lashes  of l igh t ,  var ied stepwise over a range of 2 log un i t s  
of luminance around ar~ adaptation level .  Each subject w a s  run under four 
adaptation conditions covering a t o t a l  range of 5 log u n i t s  of luminance. 
The major i n t e r e s t  here i s  i n  delineating the  change i n  brightness f o r  
s t imul i  bGth above and below the  adaptation luminance, and t o  see how t h i s  
function depends on adaptation condition. 
In  tha t  experiment ( t h e  data  are cur ren t ly  being analyzed) 
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One pa r t i cu la r ly  in t e re s t ing  finding, which has emerged from the prelim- 
inary analysis, i s  the indicat ion tha t  the brightness functions obtained show 
en in f l ec t ion  r igh t  a t  the adaptation luminance leve l ;  so the slopes f o r  
brightness changes i n  the incremental direct ions are  systematical ly  d i f fe ren t  
than the  slopes fo r  brightness changes i n  the decremental direct ions.  "his 
difference appears at a l l  the adaptation leve ls  investigated.  
due t o  successive contrast  e f f ec t s .  
It i s  perhaps 
C .  Ef fec ts  of Chromatic Adaptation on Color Naming 
{ G .  H. Jacobs) 
Chromatic adaptation e f f e c t s  have t r a d i t i o n a l l y  been invest igated i n  
the context of some var iant  of a matching procedure. 
recent demonstration by Boynton and Gordon tha t  d i r ec t  color naming, prop- 
e r l y  u t i l i zed ,  provides as  sens i t ive  a t o o l  as the matching procedures, we 
have col lected r a the r  extensive data  from three  subjects  i n  an experiment 
which w a s  designed t o  assess  chromatic adaptation e f f ec t s .  Scaled color 
naming functions have been derived f o r  conditions of neut ra l  adaptation and 
f o r  chromatic adaptation a t  636, 452, and 538 nanometer. 
s is  of these data  have been completed and i t  seems c l ea r  t h a t :  ( a )  t h i s  
technique yields  highly r e l i a b l e  data, and ( b )  quant i ta t ive ly  meaningful 
measures of chromatic e f f ec t s  can be obtained from such an approach. 
Stimulated by the 
Preliminary analy- 
D. Signal Detection and the Width of C r i t i c a l  Bands 
XR. B. Evans and L. A. J e f f r e s s )  
Work on t h i s  project  has been s tar ted.  The object of the experiment 
i s  t o  discover more about the shape of the c r i t i c a l  band of the  ea r  by a 
masking study i n  which the noise band can be varied from e i t h e r  s ide by 
the use of sharp cutoff,  high-pass and low-pass f i l t e r s .  There i s  con- 
s iderable  physiological reason t o  believe t h a t  the band i s  not symmetrical, 
and t h a t  i t  i s  t h i s  lack of symmetrythat i s  the reason f o r  the r a the r  wide 
range of estimates of the width of the c r i t i c a l  band i n  the psychoacoustical 
l i t e r a t u r e .  
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E.  Psychometric Functions f o r  an Ear Model: Effect of Duration 
( L .  A. J e f f r e s s  and A. D. Gaston, Jr .)  
Data from t h i s  study w i l l  be reported a t  the June meeting of the  Acoustical 
Society of America. 
I n  connection with work with the e a r  model, several  important f indings appeared, 
which w i l l  form the  basis  f o r  an a r t i c l e  t o  be issued a l so  as a DRL Acoustical 
Report. The findings show tha t  t he  ear appears t o  employ a kind or" running 
average o f  the  output of i t s  r e c t i f i e r  ( h a i r  ce l l s? ) ,  and t h a t  the d is t r ibu t ion  
curves f o r  noise and noise-plus-signal have shapes tha t  are  a function of the 
bandwidth of t he  f i l t e r  employed and the length of the averaging time of  the 
system. We have been able t o  f i t  human detect ion performance very closely by 
a proper choice of f i l t e r  bandwidth and in tegra tor  time-constant. 
predict ions about human performance have emerged from the study of the model 
and w i l l  be t e s t ed  with human subjects. 
An abstract  of the paper i s  included i n  the  appendix. 
Several 
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APPENDIX 
ABSTRACT 
Replication and Revisions of  Egan's Method o f  Free Reponse. 
Charles S. Watson* and Thomas L. Nichols, Defense Research Labora- 
tory, and Department of Psychology, The University of  Texas, 
Austin, Texas 78712. - Listeners performance w a s  measured under 
several  conditions similar t o  t h a t  described by Egan as the "Method 
of Free Response" [J. Acoust. SOC. Am. 33, 993-1007 (1961)l. 
addi t ion t o  randomly spacing ten s i g n a l s o f  low de tec tab i l i ty ,  
130 msec i n  duration, 500 Hz, within each five-minute l i s t en ing  
period, ten  "noise-alone intervals"  were also defined i n  each 
period. The la tenc ies  of first responses were measured, timed from 
the  onset of each observation in te rva l .  Dist r ibut ions of these 
response la tenc ies  were separately constructed f o r  signal-plus-noise 
and f o r  noise-alone in te rva ls .  Indices of de t ec t ab i l i t y  calculated 
from these d is t r ibu t ions  support Egan' s conclusions tha t  (a)  signal  
s t rength  must be increased b y  approximately 2 dB when observation 
in t e rva l s  a re  not defined f o r  the l i s tener ,  i f  he i s  t o  maintain 
h i s  performance at the  leve l  achieved with defined intervals ,  and 
( b )  t h a t  t h i s  decrement i n  performance i s  la rge ly  a function of 
uncertainty about the exact ins tan t  of s ignal  occurrence, and not 
of the  sparc i ty  of s ignals .  
from the  National Aeronautics and Space Administration t o  the 
Defense Research Laboratory. 1 
In  
[Th i s  work w a s  sponsored by a grant 
*Present address: Central  I n s t i t u t e  f o r  the  Deaf, S t .  Louis, Mo. 
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Effect  of Signal Duration on Detection f o r  an E lec t r i ca l  Model. 
Lloyd A. J e f f r e s s  and Audley D. Gaston, Jr., Department of Psychol- 
ogy, and Defense Research Laboratory, The University of Texas, 
Austin, Texas 78712. A t  the November 1965 meeting o f  the Society 
we presented the  r e s u l t s  of a ser ies  of unsuccessful attempts t o  
r ep l i ca t e  the findings of  Green, Birdsal l ,  and Tanner (J .  Acoust. 
SOC. Am. -' 29 523-531, 1957) on detection vs duration. Since then, 
s t i l l  using a fixed-bandwidth f i l t e r ,  but by changing the time con- 
s t a n t s  of the  detector we have come much closer.  Like them we have 
employed a continuous masker and a constant value of  E/N 
new da ta  y ie ld  a close f i t  t o  the i r s .  The f i l t e r  i s  followed by a 
l i n e a r  (half-wave) detector  and by an integrator  with a decay time 
o f  100 msec. A rep l ica t ion  o f t h e  experiment, t h i s  time employing 
a square-law r e c t i f i e r  (energy detector),  and using the same in te -  
grat ion time constants, yielded reasonably s imilar  r e su l t s .  [Work 
supported through a contract with Bureau of Ships and a grant from 
the  National Aeronautics and Space Administration. 1 
and our  
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DISTRIBUTION LIST FOR 
Semiannual Report f o r  Contract Nonr-3579( 04) 
f o r  t he  period of 1 December 1965 through 31 May 1966 
ana 
Quar te r ly  S ta tus  Report No. 8 f o r  NASA Number R-129-09-030-017 
f o r  t h e  period 1 March 1966 through 31 May 1966 
Copy No. 
1 - 10 
11 - 35 
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Chief of Naval Research 
Department o f  t h e  Navy 
Washington, D. C .  20360 
Attn: D r .  G. C .  Tolhurst, Code 454 
Offlce of Grants and Research Contract 
Office of Space Science and Applications 
National Aeronautics and Space Administration 
Washington, D. C .  20546 
Attn: Code SC 
Chief of Human Performance Biotechnology Division 
NASA Ames Research Center 
Moffett Field,  Cal i forn ia  
Attn: D r .  R. M. Patton 
Office of Naval Research 
Resident Representative 
The University of Texas 
2507 Main Building 
Austin, Texas 78712 
R. B. Evans, DRL/UT 
A. D. Gaston, DRL/UT 
H. A. Gaylord, DRL/UT 
G. H. Jacobs, DRL/UT 
L. A. Je f f ress ,  DRL/UT 
T. L. Nichols, DRL/UT 
Ann Tucker, DRL/UT 
R. H. Wallace, DRL/UT 
Library, DRL/UT 


Studies of auditory information processing emphasizing the application of signal detectability theory to the auditory sensory responses  Semiannual report, 1 Dec. 1965 - 31 May 1966 and eighth quarterly status report, 1 Mar. - 31 May 1966

Studies of auditory information processing emphasizing the application of signal detectability theory to the auditory sensory responses Semiannual report, 1 Dec. 1965 - 31 May 1966 and eighth quarterly status report, 1 Mar. - 31 May 1966

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