If you or a colleague are familiar with Praat, you can use this Praat script to generate variations of your stimuli where there are manipulations of the pitch contour and the duration. You'll end up with your original sound, an versions where the pitch went up or down (three different pitch contours) and for each of those, a version with the original duration, as well as a shortened duration and lengthened duration. So 9 sounds total from each original sound you have.
# Enter your sound directory here, within double quotes:
sound_dir$ = "C:\consonants"
# select your manipulations (these are multipliers of the pitch contour and duration)
pitch_up = 1.15
pitch_down = 0.85
duration_up = 1.2
duration_down = 0.8
# clear the info window
clearinfo
# list all the files in the folder
Create Strings as file list: "fileList", "'sound_dir$'\*.wav"
num_files = Get number of strings
# loop through the files
for index from 1 to num_files
select Strings fileList
filename$ = Get string: index
name$ = "'filename$'" - ".wav"
name$ = "'filename$'" - ".WAV"
Read from file: "'sound_dir$'\'filename$'"
# make a manipulation object using some default pitch analysis parameters
To Manipulation: 0.01, 75, 600
# create various pitch tiers
Extract pitch tier
Copy: "'name$'_p2"
Copy: "'name$'_p1"
Multiply frequencies: 0, 1000, pitch_down
select PitchTier 'name$'
Copy: "'name$'_p3"
Multiply frequencies: 0, 1000, pitch_up
# create various duration tiers
select Manipulation 'name$'
Extract duration tier
Copy: "'name$'_d2"
Copy: "'name$'_d1"
Add point: 0, duration_down
select DurationTier 'name$'_d2
Copy: "'name$'_d3"
Add point: 0, duration_up
for p_index from 1 to 3
for d_index from 1 to 3
select Manipulation 'name$'
plus PitchTier 'name$'_p'p_index'
Replace pitch tier
select Manipulation 'name$'
plus DurationTier 'name$'_d'd_index'
Replace duration tier
select Manipulation 'name$'
Get resynthesis (overlap-add)
Rename: "'name$'_p'p_index'_d'd_index'"
endfor
endfor
# cleanup
selectObject: "Sound 'name$'"
plusObject: "Manipulation 'name$'"
plusObject: "PitchTier 'name$'"
plusObject: "PitchTier 'name$'_p2"
plusObject: "PitchTier 'name$'_p1"
plusObject: "PitchTier 'name$'_p3"
plusObject: "DurationTier 'name$'"
plusObject: "DurationTier 'name$'_d2"
plusObject: "DurationTier 'name$'_d1"
plusObject: "DurationTier 'name$'_d3"
Remove
print finished with file: 'name$''newline$'
#pause finished with file: 'name$'
endfor