Language is studied through several areas and, among them, is the phonetics, which is concerned with analyzing in detail the sounds produced by a language. This study area is subdivided into two: a Articulatory Phonetics and the Acoustic Phonetics.Let's analyze the object of each one of them.
Articulatory Phonetics
This branch of Phonetics is concerned with the physiological and articulatory aspects of the production of sounds in a language, that is, it studies the place where sounds are produced in the vocal tract.
See in the images below the regions of the vocal tract that are analyzed by the Articulatory Phonetics during speech production:
Thus, when describing a sound, for example, the [ p ] that appears in Pact, we say it's a consonant voiceless bilabial stop. This means that, during its production, there is no vibration of the vocal cords (non-voiced) and that the air current passes through the oral cavity, not the nasal cavity, characterizing it as an oral consonant. In addition, its type of obstruction is total (occlusion), being produced by the upper and lower lips (bilabial).
Thus, according to the physiology of the vocal tract, the phonemes are classified by Acoustic Phonetics according to some specific criteria:
a) Consonants: sounds that have some obstruction in the air passage and are classified as:
- Articulation mode;
- Place of articulation;
- Voice over;
- Nasality/orality.
Example:
[ d ] - voiced alveolar stop or voiced dental stop.
b) Vowels: are sounds that have no obstruction in the air passage and are classified according to:
- Tongue height;
- Priority/ posteriority of the language;
- Rounding of the lips;
- Nasality/orality.
Example:
[ and ] (dandof) - non-rounded prior high medium.
Acoustic Phonetics
This branch of phonetics is concerned with the acoustics of speech sounds, that is, their physical aspects such as amplitude, duration, fundamental frequency and spectrum of the sound wave. This study is performed using spectrograms, waveform graphs, formant and fundamental frequency trajectories, etc.
Below is an analysis carried out by Cândida M. B. Milk, from the phoneme /R/ through a spectrogram:
In spectrogram 1 above, F3 presents values of 2074 Hz in the medial portion and 2177 Hz in the final portion. This is a clear example of retroflexion, both auditory and acoustically. This correlate reflects the acoustic pattern of the VR sequence, when /R/ is preceded by the back vowels /?/ and /u/.
The female vocal tract, being smaller than the male vocal tract, produces formants with high frequencies. Thus, since it is assumed that the formants of female speech are higher compared to those of male speech, it is also assumed that the F3 of a /R/ produced by a woman should not be below 2000 Hz, but that this F3 would present a proportional lowering, as stated by Hagiwara (1995). The example above, which summarizes the pattern found in the informant PC data, fits the results found by the aforementioned author for the /R/ postvocalic retroflex of English, from speech data female.
MILK, C. M. B. A phonetic-acoustic study of /R/ vocalized in syllabic coda position. Delta. Vol. 28 no.2 São Paulo, 2012. Available at: <http://www.scielo.br/scielo.php? script=sci_arttext&pid=S0102-44502012000200002>. Accessed on: September 12, 2017.
Thus, the sound is analyzed by the Acoustic Phonetics from the following criteria:
- Amplitude, wavelength, period and frequency;
- Speed of sound;
- Intensity and amplitude;
- Frequency and pitch (height);
- Timbre.
By Mariana Rigonatto
Graduated in Letters
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/portugues/o-que-fonetica.htm