What is Phonetics? Short answer: The study of speech sounds in all their aspects. Phonetics is about describing speech. (Note: phonetics ¹ phonics) Phonetic transcription just one aspect of this description. There are many other ways to describe speech. The methods of description give rise to different branches of phonetics. A. Articulatory phonetics: Concerned with describing (and explaining) the movements of speech structures (tongue, lips, jaw, velum, etc.). Also called articulatory kinematics (kinematics = movement).

Kinematics: Measuring the movements our body makes Kinematics: Measuring the movements our body makes. Articulatory kinematics: Movements associated with speech.

Summary: Articulatory phonetics (or kinematics) is concerned with understanding the movements that are associated with various aspects of speech; e.g., (a) What movements are involved in making specific speech sounds; i.e., how is a [t] made, how is an [s] made, etc. (b) How are speech movements planned and controlled?

B. Acoustic phonetics: Concerned with describing the acoustics of speech. Also called speech acoustics. Big questions: (1) What are the relationships between speech movements and the acoustic properties of the speech signal; e.g., when the tongue moves from a position high in the mouth to a position lower in the mouth, how does the sound pattern change (and why)?

how does the sound pattern change when the velum is up versus down (and why)? other questions like these (2) Can we make sense of phonetic categories in terms of their underlying acoustic properties; e.g., What acoustic properties do all the [t] sounds have in common (or [d] or [k] or [r] or ...)? What acoustic features are seen for sounds that are voiced (i.e., involving vocal cord vibration) vs. those that are unvoiced? What acoustic features distinguish voices that sound breathy from those that do not? Many other questions like these

[bɑ] [dɑ] [gɑ] [bɑ] [dɑ] [gɑ] Example of a speech acoustics problem: What happens to the sound pattern when the vocal tract opens? 3rd formant (F3) 2nd formant (F2) 1st formant (F1) 3rd formant (F3) 2nd formant (F2) 1st formant (F1) 3rd formant (F3) 2nd formant (F2) 1st formant (F1) [bɑ] [dɑ] [gɑ] [bɑ] [dɑ] [gɑ]

Another example of a speech acoustics problem What feature of the acoustic pattern changes as place of artic changes from bilabial (front) to alveolar (middle) to velar (back)? What feature of the acoustic pattern differ-entiates voiced stops from unvoiced stops?

These a just a few examples of the kinds of problems that are studied in acoustic phonetics or speech acoustics. The main focus is on relationships between articulation and sound.

C. Physiological phonetics C. Physiological phonetics. Concerned with the physiological mechanisms underlying speech movements. Also called speech physiology. Not always easy to distinguish physiological phonetics from articulatory phonetics. Big questions What physiological mechanisms do speakers use to control the intensity of the voice? Changes in respiratory force? Laryngeal adjustments? Some combination? What physiological mechanisms do speakers use to control the pitch of the voice? Many other questions like these.

D. Perceptual phonetics. How are speech sounds perceived D. Perceptual phonetics. How are speech sounds perceived? Also called speech perception, phonetic perception, and auditory phonetics. Big question: How do listeners recognize speech sounds, and other aspects of utterances, such as intonation (melody) and rhythm. Research questions in speech perception are the same as pattern recognition problems in any domain. What is pattern recognition? When any sort of recognition occurs, the recognition must be based on some kind of matching of the input stimulus (e.g., pattern on stimulation on the retina, pattern of stimulation in the inner ear, the pattern of stimulation on touch receptors of the skin) to patterns stored in memory.

Who are these guys? Details differ quite a bit across photos, but – no trouble with recognizing this pattern.

Who’s this guy? What do these face recognition examples tell us about the underlying pattern matching mechanism? Is it stupid and rigid or smart and flexible?

What do these examples have to do with pattern recognition for speech? A category was being recognized: The Govenator or John Kerry or a woman’s face. In speech the relevant categories are speech sounds (/b/, /p/, /r/, /l/, etc.) prosodic features (e.g., stressed syllable vs. unstressed syllable, rising intonation vs. falling intonation), attributes of the speaker (e.g., man, woman, child), etc. Image examples showed: (1) the stimulus can vary quite a bit, but (2) the pattern recognition mechanism is usually unbothered by these variations. This is also true of speech.

/æ/ (as in “cat”) spoken by a man and a child Adult Male Child Notice that the formant frequencies are quite different, yet they are both heard as good instances of /æ/.

“booed” “who’d” and “dude” (all spoken by the same man) Note how different the 2nd formant is for “dude” as compared to “booed” and “who’d”. (Due to an effect called coarticulation – more later.) Yet, like our tolerance for all of the variation in the images of Arnold, the pattern recognizers handles it. How?

Speech perception (perceptual phonetics, phonetic perception, …) is filled with problems like these. This is true of all pattern recognition sciences. Take-home lesson: Phonetics deals with describing – and attempting to explain – all aspects of speech: Articulation (articulatory phonetics, articulatory kinematics) Physiology (physiological phonetics) Acoustics (acoustic phonetics/speech acoustics) Perception (perceptual phonetics (speech perception/auditory phonetics) In this class we’ll be focusing mainly on articulation, but with some discussion of the basics of speech acoustics.