1.48.10 (from http://espeak.sourceforge.net/test/latest.html)

espeak-data/voices/test/bn

-name bengali-test
-language bn
-gender male

phsource/vowelcharts/bn

 O:	 0 584  940 2580   584  940 2580
 O	 0 536  920 2600   536  920 2600
 U	 0 368  880 2440   368  900 2440
+u:	 0 320  740 2400   320  740 2400
 i~	 0 312 2240 2844   312 2240 2844
 e~	 0 456 1960 2520   456 1960 2520
 a~	 0 724 1200 2652   724 1200 2652

phsource/vowelcharts/en

 a	 1 856 1320 2700   856 1320 2700
 a	 0 904 1320 2700   896 1340 2660
 e	 0 456 1980 2540   440 1980 2540
-i	 1 368 2100 2660   344 2146 2700
 i	 0 376 1970 2585   376 1970 2585
 o	 0 552  860 2660   552  880 2660
 u	 0 320  860 2360   320  860 2460
 n-	 0 496 1512 2380   380 1780 2540
 I2	 1 416 1800 2560   416 1800 2560
 I2	 0 408 1920 2580   416 1900 2580
+U	 1 496 1040 2560   496 1040 2560
 U	 0 445  902 2620   445  902 2620
 @L	 0 485  891 2780   450  792 2980
 a#	 0 658 1408 2460   658 1408 2460

phsource/vowelcharts/en-us

 @	 0 496 1500 2420   496 1500 2420
 @-	 0 525 1441 2340   525 1441 2340
 a	 1 670 1719 2556   710 1672 2671
-a	 1 635 1718 2519   635 1719 2522
+a	 1 664 1705 2516   568 1527 2060
 a	 0 700 1680 2506   652 1488 2470
 e	 0 456 1980 2540   440 1980 2540
 i	 0 368 2100 2660   344 2146 2700
 @L	 0 485  891 2780   450  792 2980
 a#	 0 658 1408 2460   658 1408 2460
 aa	 1 670 1719 2556   710 1672 2671
-aa	 1 635 1718 2519   635 1719 2522
+aa	 1 664 1705 2516   568 1527 2060
 aa	 0 700 1680 2506   652 1488 2470
 A:	 1 728 1200 2640   520 1400 1840
 A:	 0 728 1200 2660   712 1200 2660