Alright, we're gonna talk today about or we're gonna have a demonstration of the consonants, the
acoustics of consonants. If you remember, hopefully you've seen your acoustics of
consonants lectures on the lecture media files before you view the lab demo
of the acoustics of consonants.
The acoustics of consonants is basically based on the manner of articulation and we
discuss them under four, they are the stops, the nasals, the fricatives and the
affricates. Today what I'm gonna do here is I'm going to record a nasal sound, a fricative
sound and a stop sound and we're gonna look at the acoustic cues that have been, we
have been talking about in our class lectures. So first we'll start out with the nasals. So nasals
are sound that are always voiced, right, and they're coming through your nose, the sound is coming through your nose. I'm
having a kind of a day today and my GA will tell you that it is true. "u,mm,u" "u,ma,u" "mmmmmmmmm"
Alright, so what we see here is I have the u sound, I made the mmm sound and the u. Then I have the u, ma, u and then just the mmmmm. If you consistently look where I made, let me go ahead and play it so you can hear it again, "u,mmm, u" "u, ma,u" "mmm."
Okay, so what you see here, wherever the M sound was made, the nasal, one of the main cues for a nasal is the murmur, and the murmur happens around 200 to 300Hz, right. So you can see that the nasal murmur is one of the constant cues. I am going to draw a formant to
show, to depict those murmurs and I want you to just pay attention to that. I click something.
So if you look at this, lets just pay attention this particular spectrogram right here and this particular spectrogrm where I did the mmm sound and you can notice that red formant that you see there is the formant that shows the nasal murmur. Now, I did the vowel sound, and this is just going back to the acoustics of vowels, you can see where the F1 and F2 is, okay. So here the cue that you want to remember is the nasal murmur that you see here. That's on of the
biggest cues for your nasals. You will not see anti resonances on the
spectrogram because anti resonances are dips in the amplitude so you typically will not see
anti resonances in your spectrogram. So the main cue that you see here for
nasals in the murmur. Now we're gonna go ahead and I'm gonna
record your fricative sound and then we will see the high frequency energy
and the voicing bar which differentiates between a voiced and a voiceless fricative.
/a,s,a/ /a,z,a/ /s/ /z/ /ʃ/. Okay,
so if you see here, I'm gonna play this to you and I'm gonna show you which one represents what. First I did the /a,s,a/, then I did the /a,z,a/ then the /s/ then I did the /z/ and then we had the /ʃ / sound. So let's play it and listen to that one time. /a,s,a/ /a,z,a/ /s/ /z/ /ʃ/
Okay, so now if you look at it, what is our indication between the /a,s,a/ and the /a,z,a/ is here in the /s/ and here there is no voicing bar, it is a voiceless sound so you do not see that voicing bar right here. While if you see the
/z/ on both of these you see a voicing bar right there, which means to say that /z/ is a voiced sound which you can see like a formant, which is drawn there, which is the voicing bar. You do not see that in /s/ and you do not see it in /ʃ/ because they are
both voiceless sounds. If you look again at the high frequency energy here, look at this high frequency energy for /ʃ/ starting more intensely at this level and going up high and you can see the high frequency energy here for the /s/ and /z/ sounds. Now, you can ask me, why is that so clear on your spectrogram in the books
that you don't kinda see this lower energy and all you see is that high
energy, they photoshop the spectrograms in the book to make it more clear, but when we
do it in regular speech or even in contextual speech it is not very clear, it's not as
crystal clear to say "okay, I will only see energy at the 4000" and also if you see here,
my S and Z typically
should be, the frequencies above 4,000 but my scaling is not above 4,000. So that is probably
why we're not seeing that kind of energy in the S and Z. And let me try, I
probably will try to play around with that and post another clip to see if we can
see the frequency above the 4,000 because the S an Z are frequencies
that have energy above 4,000Hz, obviously my window here only has frequency from 0 to
4,000 and you can see here, yes, the /ʃ/ starts above 2,000Hz and that's why that energy is more predominant
there but that is an indication of high frequency energy, so what did you learn
from fricatives? The fricatives have high frequency which is one of
the representations on the spectrogram and the difference between a voiced and voiceless fricative is that
voicing bar that is present when I did the /z/, /z/ but when I did the /s/, /s/ and the /ʃ/ there is no voicing bar
so they're voiceless. Now we're gonna go ahead and do the stops, alright.
/u,u,u,b,u/ /u,b,u,b/ Okay, this actually is a good indication, let's
draw a formant.
Alright, so if you'll remember the cues we have for stops, we had for stops we had the silent gap, and if it's a voiced or voiceless sound,
the gap will be filled with a voicing bar for a voiced sound and then we had
the formant transitions which depends on the F1 and F2 transisitions
depend on the place of, actually the F2 depends on the place of articulation and the
neighboring vowel, the F1 articulation is always rising in respect to the place of
articulation. Okay, if you go back to your notes and remember that, okay. So we talked
about the silent gap, then you have a noise burst, right after when you release that sound because you
have all of this constriction in your mouth, when you release that sound you see that
noise burst, and then you see formant transmissions and then we talked about something
called the voiced onset time. It's gonna be very difficult to show a voice onset time
unless you do more analysis and extractions, so we're not gonna show the voice onset time here but on
this spectrogram we're gonna look at the silent gap, we're gonna look at the noise
bursts, we're gonna look at the voicing bar that might be present in the
silent gap if you're using a voiced sound and we're gonna talk about the
F transitions, okay. So look at this, I will play it and show you where the sounds are. /u,p,u,u,b,u,b,u,b/. Here I did the sounds in isolation,
the first two times, so if you see here this is the /u/ then I just did the /p/ whic is like what you see
here is a voice burst and right before that noise burst is a silent gap. Okay, and then
you see in the /b/ you see the noise burst right here, the release, right before the noise
burst, you see how that silent gap was filled by a formant? That's your voice
bar, meaning the /b/ sound is a voiced sound. So you have the voiceless sound which
has a silent gap which has
nothing in the silent gap, it's actually an empty gap, then you have the
noise bursts and if you remember from our lecture, the voice burst is more prominent
for voiceless sound compared to a voiced sound, it's a transient release of air, and then
you have the voicing bar and then you have the noise bursts which is slightly
shorter in duration for the voiced sound. Now go ahead and look at this when I said /u,p/ which was
together and then I said the /u,b/ which was also together. If you can see
there's a clear silent gap right there and then right after the silent gap is a noise burst which kinda gets
merged with your next sound because we will be hearing about a concept that I
haven't posted yet called coarticulation. There is an influence of the
neighboring sounds on the other so you see that silent gap and then you see the formant transitions. The
dropping and the rising, in the first one you see if your vowel, if your consonant is
following a vowel, the consonant following a vowel
the fall in the f1 and the rise in the f1 ok the CV and the VC combination so
that is something that I want you to indicate you know follow that formant
transition you can see that even more in this voiced sound that drop in the formant
transition and the rise from here and you see the voicing bars seen in here which was
not seen as a silent gap, that's the voicing bar for the /b/ sound, but there is
no voice for the voiceless sound. If you think about the stop consonants what did
we see here? We saw the silent gap. The silent gap is filled by a voicing bar if you
have a voiced sound. We have the noise burst which is not very prominent when you did
them together but when we did that in isolation you do see that noise
bursts there and then you see the formant
transition. F1 transition, falling, F1 transition, rising and remember F2 transition it
depends on the neighboring vowel and the place of articulation, so it can either rise
or fall depending on what place of articulation the sound is and whether there
is what kind of the vowel is whether its an /a/ or it's an /i/. If you go back to see whether what I'm saying make sense if
you look at formant transition on your PDF page 3 the last slide when it says formant
transitions and you can see how that F2 varies with the place of
articulation and the neighboring vowel. This is what I'm meaning here and I haven't demonstrated that
on your spectrogram but that is what I mean F2 transitions it depends
on your place of articulation and varies with the neighbouring vowel while
your F1 translation in respect to of the place of articulation is always rising in CV
combinations so there is always rising in CV combination, always is falling in
the VC combination, okay. I know this is a very brief overview but I'm
basically when I try to show here is the cues and this will help you when you
look at these cues will help you with your lab two casue your lab two is gonna talk
about that murmur. You're gonna have to draw that. You are going to have to point
to the on the graph you're gonna have to point to the cues that you
differentiate the stops from and you're also gonna talk about a high frequency
energy in one of your lab questions. Alright, well good luck!