﻿314 
  Prof. 
  L. 
  T. 
  More 
  on 
  the 
  Localization 
  

  

  agreement 
  between 
  the 
  experimental 
  and 
  theoretical 
  curves. 
  

   In 
  figures 
  8 
  to 
  11 
  inclusive 
  there 
  is 
  a 
  progressively 
  increasing 
  

   discrepancy 
  between 
  the 
  curves. 
  In 
  all 
  cases 
  I 
  noted 
  

   changes 
  of 
  direction 
  which 
  followed 
  a 
  sinusoidal 
  curve, 
  but 
  

   there 
  was 
  besides 
  an 
  increasing 
  difficulty 
  of 
  locating 
  sounds 
  

   which 
  theoretically 
  should 
  be 
  from 
  the 
  right. 
  When 
  the 
  

   frequency 
  1024 
  d.v. 
  was 
  reached 
  in 
  the 
  series, 
  all 
  the 
  sounds 
  

   apparently 
  came 
  from 
  the 
  left 
  in 
  varying 
  degrees. 
  The 
  

   judgement 
  for 
  these 
  high 
  frequencies 
  was 
  also 
  somewhat 
  

   further 
  confused, 
  as 
  shown 
  by 
  an 
  inclination 
  to 
  locate 
  sounds 
  

   near 
  the 
  middle 
  or 
  slightly 
  to 
  the 
  left. 
  With 
  practice 
  the 
  

   regularity 
  of 
  the 
  curves 
  was 
  improved 
  but 
  they 
  invariably 
  

   showed 
  this 
  decided 
  preference 
  in 
  location. 
  On 
  trying 
  the 
  

   judgement 
  of 
  Mr. 
  Evens 
  in 
  locating 
  directions, 
  I 
  found 
  that 
  

   he 
  had 
  an 
  even 
  more 
  decided 
  preference, 
  but 
  his 
  was 
  for 
  the 
  

   right 
  side, 
  and 
  also 
  that 
  1024 
  d. 
  v. 
  was 
  practically 
  the 
  limit 
  of 
  

   his 
  power 
  of 
  determining 
  direction 
  in 
  this 
  manner. 
  

  

  The 
  cause 
  for 
  this 
  preference, 
  which 
  agrees 
  with 
  

   Dr. 
  Dunlap's 
  conclusions, 
  is 
  unknown, 
  but 
  there 
  are 
  some 
  

   facts 
  which 
  apparently 
  have 
  a 
  bearing 
  on 
  it. 
  My 
  own 
  

   hearing 
  is 
  about 
  normal, 
  although 
  my 
  right 
  ear 
  is 
  a 
  little 
  

   more 
  acute. 
  Mr* 
  Evens 
  is 
  not 
  normal, 
  as 
  he 
  heard 
  with 
  

   considerable 
  difficulty 
  with 
  his 
  right 
  ear. 
  In 
  both 
  cases 
  

   then 
  the 
  region 
  of 
  preference 
  lies 
  on 
  the 
  weaker 
  side. 
  In 
  

   the 
  next 
  place 
  the 
  half 
  wave-length 
  for 
  frequency 
  1024 
  is 
  

   about 
  16 
  cm._, 
  the 
  average 
  distance 
  between 
  the 
  ears. 
  For 
  

   waves 
  of 
  such 
  length 
  the 
  head 
  must 
  cast 
  a 
  very 
  appreciable 
  

   sound 
  shadow 
  and 
  so 
  make 
  possible 
  the 
  determination 
  of 
  

   direction 
  by 
  an 
  immediate 
  comparison 
  of 
  the 
  intensities 
  at 
  

   the 
  two 
  ears. 
  The 
  mind 
  would 
  then 
  have 
  no 
  training 
  for 
  

   phase-differences 
  with 
  these 
  waves. 
  But 
  these 
  facts 
  are 
  

   possibly 
  only 
  coincidences. 
  

  

  We 
  may 
  judge 
  then 
  from 
  these 
  experiments 
  that 
  c" 
  

   (n 
  = 
  512) 
  is 
  near 
  to 
  my 
  limit 
  for 
  accuracy 
  of 
  judgement 
  

   by 
  phase-differences 
  and 
  that 
  accuracy 
  decreases 
  for 
  higher 
  

   pitches, 
  becoming 
  untrustworthy 
  at 
  a 
  pitch 
  of 
  about 
  

   1024 
  d.v. 
  

  

  Although 
  no 
  detailed 
  investigation 
  was 
  made 
  with 
  sounds 
  

   of 
  a 
  higher 
  pitch, 
  yet 
  a 
  qualitative 
  trial 
  with 
  a 
  fork 
  of 
  pitch 
  

   ,3000 
  d. 
  V. 
  approximate, 
  showed 
  that 
  absolutely 
  no 
  sensation 
  

   of 
  direction 
  existed. 
  The 
  fork 
  was 
  struck 
  and 
  then 
  held 
  

   close 
  to 
  the 
  orifice 
  o£ 
  the 
  T-piece, 
  while 
  the 
  latter 
  was 
  slowly 
  

   moved 
  to 
  the 
  right 
  or 
  left. 
  The 
  only 
  result 
  was 
  the 
  sensation 
  

   of 
  a 
  very 
  shrill 
  uniform 
  sound 
  a 
  long 
  way 
  off, 
  whose 
  direction 
  

   was 
  impossible 
  to 
  locate. 
  

  

  It 
  has 
  not 
  yet 
  been 
  shown 
  whether 
  the 
  perception 
  of 
  

  

  