Linguistics > Phonetics > Acoustic Phonetics

Acoustic Phonetics sits at the intersection of linguistics and physics, focusing on the physical properties of the sounds produced in human speech. This subfield of phonetics examines how speech sounds are generated, transmitted, and received through the study of their acoustic properties, including the frequency, amplitude, and duration of sound waves.

In the production of speech, the human vocal apparatus, including the lungs, vocal cords, and articulators (tongue, teeth, and lips), creates complex sound waves. Acoustic Phonetics quantifies these sound waves using measurements such as frequency (the number of vibrations per second, measured in Hertz), amplitude (the sound wave’s peak displacement, which correlates with loudness), and duration (the length of time a sound is sustained).

Acoustic Phonetics also involves the analysis of spectrograms, which are visual representations of sound showing the frequencies present in a sound and how they change over time. Spectrograms provide a way to dissect the acoustic structure of speech sounds by illustrating the resonant frequencies of the vocal tract, known as formants. The first two formants, F1 and F2, are especially important in distinguishing different vowel sounds.

For example, the vowel /i/ (as in “see”) can be characterized by its formant frequencies:
\[ F1 \approx 300Hz \]
\[ F2 \approx 2200Hz \]

Additionally, Acoustic Phonetics investigates how different physical properties of the sounds are integrated into the linguistic system, aiding in processes such as phoneme recognition and speaker identification. This field uses tools and techniques from digital signal processing to capture and analyze speech sounds, enabling researchers to develop models that explain how these sounds function in human languages.

Understanding Acoustic Phonetics is crucial for applications such as speech synthesis, speech recognition, forensic linguistics, and language teaching. Through the rigorous study of sound waves and their interactions, researchers can gain deeper insights into the nature of spoken language and its variability across different contexts, speakers, and languages.