Categorical Perception Response Sheet

I.	 Identification:  You will hear 21 occurrences of /pae/ and /bae/ (the “a” sound in the words bat and pat). Circle the one that you hear.

1.	/pae/	/bae/	8.	/pae/	/bae/	15.	/pae/	/bae/	
2.	/pae/	/bae/	9.	/pae/	/bae/	16.	/pae/	/bae/	
3.	/pae/	/bae/	10.	/pae/	/bae/	17.	/pae/	/bae/	
4.	/pae/	/bae/	11.	/pae/	/bae/	18.	/pae/	/bae/	
5.	/pae/	/bae/	12.	/pae/	/bae/	19.	/pae/	/bae/	
6.	/pae/	/bae/	13.	/pae/	/bae/	20.	/pae/	/bae/	
7.	/pae/	/bae/	14.	/pae/	/bae/	21.	/pae/	/bae/	

II.	Discrimination:  You will hear 40 syllable triads.  The first two syllables will be different from each other.  The last (X) syllable will be identical to either the first (A) syllable or the second (B) syllable.  Circle the syllable (A or B) that you think the last (X) syllable is identical to.  This goes by really fast.  Do your best.

1.	A	B	11.	A	B	21.	A	B	31.	A	B	
2.	A	B	12.	A	B	22.	A	B	32.	A	B	
3.	A	B	13.	A	B	23.	A	B	33.	A	B	
4.	A	B	14.	A	B	24.	A	B	34.	A	B	
5.	A	B	15.	A	B	25.	A	B	35.	A	B	
6.	A	B	16.	A	B	26.	A	B	36.	A	B	
7.	A	B	17.	A	B	27.	A	B	37.	A	B	
8.	A	B	18.	A	B	28.	A	B	38.	A	B	
9.	A	B	19.	A	B	29.	A	B	39.	A	B	
10.	A	B	20.	A	B	30.	A	B	40.	A	B	

Identification Task  Scoring:
1.	Circle all of the /be/ responses you made in the identification task.
2. 	Each of the syllables you heard in the identification task had a voice onset time 
(VOT) that varied between 0 and 60 ms in 10 ms intervals. These VOT values are indicated in Table 1. For each stimulus that item that you identified as a /bae/, put a “1” in the cell next to that item number in the table. For the remaining stimulus items, which you identified as /pae/ enter a “0” in the corresponding cell.
3. 	Compute column totals for each VOT interval. Then compute the percentage of 
correct /bae/ responses by dividing this total by 3 and multiplying the result by 100.
4. 	Graph your data.

Table 1
VOT	
0ms	10ms	20ms	30ms	40ms	50ms	60ms	
item#	/be/	item#	/be/	item#	/be/	item#	/be/	item#	/be/	item#	/be/	item#	/be/	
4		2		7		5		1		3		6		
11		8		10		12		14		13		9		
17		16		18		21		19		15		20		
total		--		--		--		--		--		--		
:	3		3		3		3		3		3		3	
%														

Discrimination Task Scoring: Table 2 presents the VOT values associated with each of the syllables in each stimulus triad. As you can see, for each triad, the A and B syllables differed by 20 ms VOT. Table 2 also reveals that each possible combination of ABX (i.e., ABA, ABB, BAB, and BAA) was presented twice. The correct response for each trial is indicated by the letter in boldface.

Table 2:  VOT values for each A, B, and X member of each stimulus trial.
#	A	B	X	#	A	B	X	#	A	B	X	#	A	B	X	
1.	0	20	0	11.	20	40	20	21.	0	20	0	31.	30	50	50	
2.	50	30	30	12.	30	50	50	22.	60	40	40	32.	50	30	30	
3.	20	40	40	13.	10	30	30	23.	30	10	10	33.	20	0	20	
4.	30	10	10	14.	40	20	40	24.	40	60	40	34.	20	40	20	
5.	30	10	10	15.	30	10	30	25.	10	30	30	35.	30	10	30	
6.	60	40	40	16.	40	60	40	26.	60	40	60	36.	40	20	40	
7.	0	20	20	17.	30	50	30	27.	0	20	20	37.	20	40	40	
8.	60	40	60	18.	40	60	60	28.	40	60	60	38.	40	20	20	
9.	40	20	20	19.	50	30	50	29.	20	0	0	39.	50	30	50	
10.	10	30	10	20.	20	0	0	30.	30	50	30	40.	10	30	10	

1.	Using Table 2, circle your correct discrimination responses on your answer sheet.
2.	Table 3 groups stimulus items into 20ms VOT intervals. For the items in each interval, 
	give yourself a “1” if you made a correct discrimination on the trial, and a “0” otherwise. 
3.  	compute your column totals, then divide each by 8.  Multiply the result by 100 to 
compute the percentage of correct discriminations for each VOT interval,
4.	Graph your results on the same graph that you plotted your identification results.
	Use the center of each category to plot your results (e.g., for 0-20ms VOT, plot your 
percentage correctly discriminated so that it corresponds to 10 VOT on the X-axis.

Table 3: Correct syllable for 8 stimulus trials within each of five 20ms VOT intervals.
0-20ms (10)	10-30ms (20)	20-40ms (30)	30-50ms (40)	40-60ms (50)	
item#	correct	item#	correct	item#	correct	item#	correct	item#	/correct	
1	A		5	B		3	B		2	B		6	B	
4	B		10	A		9	B		12	B		8	A	
7	B		13	B		11	A		17	A		16	A	
20	B		15	A		14	A		19	A		18	B	
21	A		23	B		34	A		30	A		22	B	
27	B		25	B		36	A		31	B		24	A	
29	B		35	A		37	B		32	B		26	B	
33	A		40	A		38	B		39	A		28	B	
total										
:8										
%