1. Vowel Formants in a Spectogram Nural Akbayir, Kim Brodziak, Sabuha Erdogan

2. Introduction: Vowel Formants A concentration of acoustic energy around a particular frequency of air in vocal tract A concentration of acoustic energy around a particular frequency of air in vocal tract Refers to peaks in a harmonic spectrum Refers to peaks in a harmonic spectrum Arises from a resonance in the vocal tract Arises from a resonance in the vocal tract

3. Vowel Formants Important to distinguish vowel sounds Important to distinguish vowel sounds Essential components in the intelligibility of speech Essential components in the intelligibility of speech Difference in formants for different people Difference in formants for different people

4. Vowel Formants An average human assumes five formants, 0 to 5500 An average human assumes five formants, 0 to 5500 Computation of the formants of a straight tube Computation of the formants of a straight tube Tube = 16 cm, shortest wave lenght = 64 cm, 352 m/s: resonance frequency of 352/ 0,64 = 550 Hz Tube = 16 cm, shortest wave lenght = 64 cm, 352 m/s: resonance frequency of 352/ 0,64 = 550 Hz Original speech signal female adults: 11 kHz Original speech signal female adults: 11 kHz male adults: 10 kHz male adults: 10 kHz young children: 20 kHz young children: 20 kHz

5. Vowel Formants In a spectogram displayed as dark bands In a spectogram displayed as dark bands The darker, the stronger (more energy, audible) The darker, the stronger (more energy, audible) Numbered upwards from the lowest frequency (F1 – F5) Numbered upwards from the lowest frequency (F1 – F5)

6. Vowel Formants Front vowels have a greater distance between F1 and F2 Front vowels have a greater distance between F1 and F2 Back vowels have F1 and F1 so close that they touch Back vowels have F1 and F1 so close that they touch

7. Vowel Formants Monophthong vowels have strong stable formants Monophthong vowels have strong stable formants Voiced vowel [i] = periodic vibration of the vocal folds produces a series of harmonic tones Voiced vowel [i] = periodic vibration of the vocal folds produces a series of harmonic tones

8. Examples F1F2F3F4 F1F2F3F4 He 283,082128,732932,503417,28 Who 676,33 1971,58 3164,26 5030,10 Hard 597,921076,332587,163537,44 Head 432,251674,412469,943391,17 Had 576,261571,952507,593423,74

9. Vowel Formants F1 can vary from 300 Hz to 1000 Hz F1 can vary from 300 Hz to 1000 Hz - the lower it is, the closer is the tongue to the roof of the mouth - the lower it is, the closer is the tongue to the roof of the mouth F2 can vary from 850 Hz to 2500 Hz F2 can vary from 850 Hz to 2500 Hz - F2 value is proportional to frontness or backness of the highest part of the tongue - Lip rounding causes a lower F2 than with unrounded lips F3 = determining the phonemic quality F3 = determining the phonemic quality F4 & F5 =determining the voice quality F4 & F5 =determining the voice quality