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Articulatory phonetics studies how the moving structures of the vocal tract produce speech. Airflow supplies energy; vocal fold vibration can provide a repeating source; the tongue, lips and other articulators shape or interrupt the flow. Producing voice and shaping recognizable speech are related but distinguishable processes.^[ref]

A simple observation compares a sustained “mmm” with a sustained “sss”. Lightly touching the outside of the throat can help detect the vibration accompanying voicing, while a mirror shows the different lip configurations. This is a qualitative demonstration: the external sensation alone does not measure the detailed motion of the vocal folds.

Descriptions of consonants commonly distinguish place of articulation, where a constriction is formed, from manner of articulation, how the airflow is modified. These descriptions explain why changing the tongue or lips can change the recorded sound without changing the source of airflow. Acoustic phonetics measures the resulting signal, while articulation describes its physical production.

A bilabial consonant uses the two lips to form its principal constriction. The term specifies place of articulation; it leaves manner of articulation and voicing to be stated separately. The lower lip approaches the upper lip rather than the upper teeth.^[ref]

The sounds [p], [b] and [m] share a bilabial closure. The first two are oral stops, while [m] permits nasal airflow; their shared lip position therefore does not determine whether sustained sound is possible during closure. A mirror provides direct evidence of the lip configuration, but it cannot alone establish the state of the vocal folds or the soft palate.

Canadian English names English varieties used in Canada, with variation across regions, communities and speakers. For a scientific account, a pronunciation feature must be operationalized and measured rather than treated as a property shared identically by every speaker. Sociolinguistics and acoustic phonetics provide complementary methods for those comparisons.

An acoustic study by Sky Onosson compared Canadian, American Western and American Northern speech through vowel durations and formant trajectories, examining Canadian raising and the effect of a following consonant's voicing.^[ref] A useful replication would record comparable words and contexts, align vowel intervals, and compare trajectories under a stated time normalization. That separates a pronunciation's changing acoustic shape from differences caused merely by speaking rate or the analysis point.

Catherine Anderson is a linguist at McMaster University who authored Essentials of Linguistics by Catherine Anderson and coauthored its expanded second edition. The first edition makes introductory phonetics concrete through articulator descriptions, consonant classification and the distinction between sounds and writing.^[ref]

Her institutional profile records a doctorate in linguistics from Northwestern University and describes work on teaching and accessibility in university learning.^[ref] Her textbook contribution supplies a route from everyday speech to explicit categories such as place of articulation, manner of articulation and voicing.

A consonant is a speech sound articulated with a closure or constriction that significantly shapes or interrupts airflow. Its physical description typically specifies place of articulation, manner of articulation and voicing. These describe where the articulators act, how the air passes and whether the vocal folds vibrate.^[ref]

The sounds [p] and [b] both involve the lips and a closure, but differ in their usual voicing classification. A sustained [m] also closes the lips, while opening a route through the nose: an oral closure does not imply that all airflow stops. The distinction between a plosive and a nasal consonant therefore depends on airflow paths, not merely the fact that two lips touch.

The category concerns speech sounds, rather than letters: a written symbol's name and its sound in a particular word are different objects of study. A consonant can also function as a syllabic consonant, so a syllable nucleus is not invariably a vowel.

A fricative is a consonant produced with a narrow constriction that generates sustained turbulent airflow and its associated noise. The articulators approach closely without creating the complete oral closure of a plosive. Place of articulation and voicing further distinguish different fricatives.^[ref]

Sustain [f] and then [v]. Both use the lower lip and upper teeth, but the second normally adds vocal fold vibration. A spectrogram can display a noise component and, where present, periodic structure. The physical source of the noise is the constricted airflow, while the vocal tract shapes its spectrum. Merely calling a sound unvoiced does not identify it as a fricative.

A labiodental consonant forms its principal constriction between the lower lip and upper teeth. This is a place of articulation, distinct from the two-lip constriction of a bilabial consonant. It does not by itself specify voicing or manner of articulation.^[ref]

The familiar sounds [f] and [v] are labiodental fricatives. Comparing them keeps the constriction location similar while changing the usual voicing category. Comparing [f] with [p] instead changes both the contact surface and the airflow mechanism. A mirror can show lower-lip contact with the upper teeth, while acoustic phonetics examines the resulting noise and periodicity.

Manner of articulation describes how a speech constriction controls airflow. A plosive builds an oral closure that can be released; a fricative narrows the passage enough to generate turbulent airflow. A nasal consonant can close the oral passage while allowing air to pass through the nose.^[ref]

Compare [p], [f] and [m]. Their differences cannot be reduced to whether the sound comes from the front of the mouth: the closure, friction-producing narrowing and nasal route produce different acoustic consequences. A sustained [f] contains a noise component generated by airflow through a narrow constriction; a sustained [m] combines voicing with a different resonant airway.

Manner of articulation complements place of articulation. Two sounds can share a place but differ in manner, so identifying only the location of a constriction leaves the mechanism underspecified.

A nasal consonant combines a constriction or closure in the mouth with an open airflow route through the nose. Lowering the soft palate opens that route; the mouth can remain closed at the consonant's place of articulation. A sustained [m] therefore produces sound despite closed lips, whereas closing both routes stops sustained outward flow.^[ref]

Compare [m], [n] and [ŋ]. They share a nasal manner of articulation, while their oral closures occupy different places. Comparing [m] with [b] instead holds the bilabial closure approximately fixed while changing the available airflow route. Voicing and the resonant vocal tract shape the recorded signal; the written letter alone does not specify those physical properties.

A pitch contour describes how perceived pitch varies over an utterance. For speech with voicing, a common measurable correlate is the fundamental frequency $F_0(t)$ of vocal fold vibration. A rising estimated $F_0(t)$ indicates increasing repetition rate; stretches without sufficiently periodic vibration need not have a meaningful estimate.^[ref]

For an ideal periodic segment whose repetitions are separated by $T=0.01\mathrm{s}$, $F_0=1/T=100\mathrm{Hz}$. Detecting repetition at $2T$ instead produces an erroneous 50 hertz estimate, illustrating why a visually smooth pitch contour can still contain an octave error. Noise, the analysis interval and the allowed frequency range affect the estimate. Current Praat documentation distinguishes methods intended for speech intonation from methods intended for other periodicity measurements.^[ref]

A pitch contour is not the same as a formant contour: changing the fundamental frequency changes the repetition rate, whereas formants describe the resonant spectral structure shaped by the vocal tract.

Place of articulation identifies where speech articulators form a constriction or closure. A description can specify an active articulator, such as the tongue, and the surface it approaches. A bilabial consonant uses both lips; a labiodental consonant uses the lower lip and upper teeth; a velar consonant involves the back of the tongue near the soft palate.^[ref]

For example, [f] and [v] share a labiodental location, while their typical voicing classifications differ. Conversely, describing a sound as a fricative specifies manner of articulation without identifying which constriction produces it. The paired descriptions make the physical classification more informative.

The place is an approximate region and relation between articulators, rather than a single universal coordinate in the mouth. Neighboring sounds can change the detailed movement while leaving the broad category useful.

A plosive is an oral stop consonant: articulators form a complete oral closure, pressure can build behind it, and releasing the closure can produce a brief burst. During the closure, the nasal airflow route is normally closed. This distinguishes the mechanism from a nasal consonant with the same oral place of articulation.^[ref]

The sounds [p] and [b] both use a bilabial closure, while differing in their usual voicing classification. A recording of a released [p] can show a closure interval followed by a burst and the following sound. The release need not always be audibly strong, so an absent obvious burst alone does not show that no closure occurred. Articulation and the observed acoustic trace provide complementary evidence.

A velar consonant forms its main constriction between the back of the tongue and the soft palate. The label identifies a place of articulation. The soft palate's separate role in controlling the nasal airflow route means that velar place does not itself imply a nasal manner of articulation.^[ref]

The sounds [k] and [g] are velar oral stops, while [ŋ] is a velar nasal consonant. All involve a similar oral constriction region, but they differ in airflow route and usual voicing. The precise contact position can also shift with neighboring vowels. Describing a region of contact is therefore more informative than imagining one fixed point used identically in every utterance.

Voicing is the use of vocal fold vibration during speech production. Airflow and the mechanical state of the vocal folds can sustain repeated opening and closing, introducing a periodic component into the emitted sound. The fundamental frequency of this repetition contributes to perceived pitch.

A practical comparison is to sustain [s] and [z] while gently feeling the front of the throat: the added vibration during [z] makes the distinction tangible. Both involve a similar oral constriction, so the comparison separates voicing from place of articulation and manner of articulation. The physical state of the glottis is an additional dimension of the sound.^[ref]

A binary transcription is a useful classification rather than a complete time record. Voicing can begin, end or weaken during a sound, and an acoustic estimate depends on the interval examined. A pitch contour should therefore distinguish missing or unreliable periodicity from a measured low fundamental frequency.