LING 323 Lecture Notes - Lecture 1: Voice-Onset Time, Acoustic Phonetics, Formant
23 Jun 2018
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Ling 330
Acoustic phonetics: consonants
A. For sound comparisons, you´ll use the following files. Use WAVESURFER to do the
analyses.
labial sounds alveolar sounds palatal sounds velar sounds
spa.wav sta.wav ska.wav
apha.wav atha.wav akha.wav
aba.wav ada.wav aga.wav
ama.wav ana.wav anga.wav
ala.wav aja.wav awa.wav
ara.wav
asa.wav asha.wav
1. Acoustic attributes of a stop
Open apha.wav. Notice…
• the silence due to completely closing off the airflow
• the burst of air resulting from the airflow being released when the closure is released. The
airpressure has built up, so it has high intensity for a short duration
• the noise following the burst, resulting from the aspiration.
• where the aspiration ends and the following vowel begins
2. Acoustic attributes of an oral stop versus an nasal stop
Open atha.wav and ana.wav. Both [th] and [n] are articulated at the alveolar ridge, but [th] is an
oral stop, whereas [n] is a nasal stop. Notice…
• during the closure period of the stops, there is relative silence in the [th], where as for the [n],
there is quite much energy. This is because, in the production of nasal stops, the airflow
continues to go through the nose. So the low amplitude energy you see is from this nasal
airflow.
• you will see the same patterns by comparing other pairs of oral and nasals stops, such as the
bilabial stops [b, ph, m] or the velar stops [g, kh, ŋ].
3. Acoustic attributes of voicing and aspiration
Open sta.wav, atha.wav and ada.wav. The sounds [t], [th] and [d] are articulated at the alveolar
ridge. [t] and [th] are both voiceless, although [t] is unaspirated and [th] is aspirated. By contrast,
[d] is a voiced. Notice…
• there is little low frequency energy during the closure of the [t] and [th], whereas for [d] there
is quite much low frequency energy which looks like a band. This band of energy is called
a ”voice bar” which reflects the fundamental frequency from the vocal fold activity for voiced
sounds.
• in both [atha] and [ada] the voice bar is evident in the [a] following the stop. In [ada] the voice
bar continues from the [d] into the [a], whereas in [atha] the voice bar does not start until the
end of the aspiration at the end of the stop.
• the duration between the stop burst and the start of the voice bar is called ”voice onset time”
(VOT). For voiceless stops like [th] the VOT is a positive value since the burst starts before the
voice bar, whereas for voiced sounds like [d] the VOT value is negative since the voice bar
starts before the burst.
• Whereas [th] has aspiration following the closure, [t] in [sta] does not. Notice that the
voicebar begins right after the burst. Its VOT is intermediate to [th] and [d]. In [sta] if you
remove the [s] and listen to only [ta], it will likely sound like [da]. That is because it´s VOT is
closer to the phoneme /d/ than it is to /p/. We need the /s/ there to perceive it as a [t].
• you will see the same kinds of patterns by comparing the corresponding set of sounds produced
at the alveolar ridge and at the velum.
4. Acoustic attributes of place of articulation
Keep apha.wav open. Open atha.wav and akha.wav. This may be difficult to see in the current
examples, but see if you notice…
• the change in the second formant from the aspiration to the vowel. The direction of the formant
movement is associated with place of articulation. If you´d like to look more at this, see if you
find the pattern across
aba.wav, ada.wav, and aga.wav
ama.wav, ana.wav, and anga.wav
5. Acoustic attributes of fricatives
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Acoustic phonetics: consonants: for sound comparisons, you ll use the following files. Use wavesurfer to do the analyses. labial sounds spa. wav apha. wav aba. wav ama. wav alveolar sounds sta. wav atha. wav ada. wav ana. wav ala. wav ara. wav asa. wav palatal sounds aja. wav asha. wav velar sounds ska. wav akha. wav aga. wav anga. wav awa. wav: acoustic attributes of a stop. Notice : the silence due to completely closing off the airflow, the burst of air resulting from the airflow being released when the closure is released. Both [th] and [n] are articulated at the alveolar ridge, but [th] is an oral stop, whereas [n] is a nasal stop. Notice : during the closure period of the stops, there is relative silence in the [th], where as for the [n], there is quite much energy. This is because, in the production of nasal stops, the airflow continues to go through the nose. The sounds [t], [th] and [d] are articulated at the alveolar ridge.
