Consonants Pt. 2

Stop consonants involve complete obstruction of airflow in the oral cavity followed by a release.
They can be voiced (with vocal fold vibration) or voiceless (without vocal fold vibration).

Production: Involves a buildup of pressure, and stops are generally brief.
Voiceless stops: Longer duration compared to voiced stops, which have shorter bursts.

Voice Bars: Present in voiced stop consonants; indicate vocal fold vibrations during production.
Burst: The sudden release of pressure that occurs after the stop.
Aspiration: A burst of breath following the release of voiceless stop consonants (e.g., "p" in "pat").
- Voiced stop consonants typically do not show aspiration.
Formant Transitions: Changes in frequency that occur as the stop consonant transitions to a vowel or another consonant.
- Important for distinguishing phonemes based on neighboring sounds.
Voice Onset Time (VOT): The time interval between the release of the stop consonant and the onset of vocal fold vibration for the following vowel.
- Voiced consonants have shorter or even negative VOT; voiceless consonants have longer, positive VOT.
Stop Gap: The period of silence before the burst occurs, indicating where the airflow was obstructed.

Voiceless stop consonants are produced with aspiration and have longer VOT.
Voiced stop consonants are shorter and do not usually exhibit aspiration.
Stops are identified by their unique combination of bursts, aspiration, voice bars, and VOT.

Fricatives have a narrow constriction rather than a complete stop, allowing airflow to continuously pass.
They produce a continuous noise rather than a burst, making them distinct from stops.
- Example: The difference between "stop" (complete obstruction) and "fricative" (narrow constriction).

Noise: Frication noise varies in frequency and intensity across different fricatives.
- The spectrogram shows distinct energy concentrations based on whether the fricative is voiced or voiceless.
Sibilants: A category of fricatives (like "s" and "sh") that have higher energy and are produced with narrower constrictions.

Cues for Perception: Key cues include frication noise and formant transitions.
Energy Levels: Indicates the intensity of the fricative sounds based on where those sounds occur on the spectrogram.

Nasals (m, n, ng) involve airflow through the nasal cavity with low energy levels on the spectrogram.
Approximants (l, r) are produced with less constriction in the vocal tract, often resonating similarly to vowels.

Nasometer: Assesses nasal vs. oral airflow, useful for diagnosing hypo/hypernasality.
Electromagnetic Articulography (EMA): Provides visual feedback on tongue movement in real-time for speech production.
Electropalatography (EPG): Used for visual feedback on tongue-to-palate contact, particularly useful for therapy targeting specific sounds.

Understanding the production and acoustic features of consonants is crucial in speech-language pathology, particularly in articulation therapy and assessment.