Formant analysis in dysphonic patients and automatic Arabic digit speech recognition

Table 5 Comparison between the first four formants of the vowel/a/in the tested Arabic digits in different voicing disorders

Voice Disorders	F1 (Hz)			F2 (Hz)			F3 (Hz)			F4 (Hz)
	Mean	SD	P Value (t test)	Mean	SD	P Value (t test)	Mean	SD	P Value (t test)	Mean	SD	P Value (t test)
Normal	710	4		1492	53		2467	16		3647	45
Cyst	528	107	0.001 >	1145	107	0.01	2452	115	0.001 >	4001	115	0.05
LPRD	747	107	0.03	1345	107	0.02	2398	115	0.001 >	3668	115	0.01
Spasmodic dysphonia	582	201	0.001 >	1178	101	0.01	2687	132	0.002	3536	132	0.04
Sulcus	658	324	0.04	1202	108	0.02	2512	439	0.03	3532	118	0.001 >
Nodules	612	104	0.001 >	1301	75	0.005	2598	360	0.02	3899	166	0.04
Polyp	821	377	0.01	1431	28	0.001 >	2880	250	0.005	3892	83	0.001 >

The speech obtained from all voice disordered patients had significantly (P < 0.05, Student's t-test) deviated formant values from that of normal. For instance, vocal fold cysts patients had F1 of 528 Hz, which has 107 Hz standard deviation (SD) from F1 of normal subjects. Similarly, F2 of the same disorder (1145 Hz) has SD of 107 Hz from that of normal. F1 value deviated most from normal in vocal fold cysts, followed by spasmodic dysphonia. The same was true for F2 value. F3 that corresponds to phoneme quality had the highest deviation from the normal in vocal fold polyps group, while F4 that corresponds to voice quality deviated most in vocal fold cysts.

ISSN: 1475-925X