The next thing we're gonna talk about, I'm gonna briefly start here but I'm
gonna probably continue this in the next lecture is we're going to talk about fricatives.
Fricatives have five articulatory positions, what are they?
Some of the fricative sounds are /f/ and the /v/, the fan and van. Then the linguadental which is the the /θ/ and the /ð/
I can say this, the thumb and the this because most of my linguadentals actually become my
avelolar sounds. If you hear me say thank you it's very difficult I have to
really think through and I usually will say thank you.
Okay, if you can hear the difference in me saying thank you vs. thank you. My thank you is
one which is very common for me to say so linguadentals do not exist in my
language so it's very hard for me to produce those sounds. Then the alveolar is
the /s/ and the /z/.
If you see where your tongue is, okay, it's right behind your aveolar ridge. Then the palatal is the
/ʃ/ and the /Ʒ/, where your tongue is. Then the glottal is the /h/, /h/, okay. So, you have different, fricatives
have different articulatory positions. If you see here
the labiodental, the linguadental, and then the alveolar, the palatal, and then the
glottal is in the back where your vocal folds are, that's the glottal. The fricatives are non-resonant
consonants. Remember we talked about this, what are the characteristics of non
resonant consonants? There is minimal airflow or restricted air flow, that's the
term, no or minimal forment structure and voiced or voiceless
but this fricative is continuant. Continuant is something that can be prolonged, so if I
go "sssssssss" "shhhhhhhh" "ffffffffff," see how I can prolong those sounds? Hence, fricatives are non resonant, continuant sounds. So if I were to ask you to give me an example of a non resonant continuant sound, you should be able to give an example of a fricative.
So again here,
restricted air flow, the restricted air flow is caused by constrictions and occulasions
within the vocal tract. There is a presence of audible noise I don't have
to do that again, if you again go "ssssssssss" that's the presence of audible noise and
this noise makes speech audible, okay. The fricative noise originates at the
articulatory construction that's what you hear a difference in how does audible noises
are. So let's do this again, "ffffffffffff" "ssssssss" "shhhhhhhhhhhhhh" "zzzzzzzzzzzzzzz"
See how the fricative noise that originates at the articulatory constriction had
different sounding audible noises. It has voiced and voiceless cognates so /s,z/ /ʃ, Ʒ/ /f,v//
You see the difference? Let's do this one more time, I want you to think through this, I want you to
really be able to pay attention so it's a non-resonant sound, restricted airflow,
restriction happens in occulations in the vocal tract or the oral cavity okay and
then their presence of audible noise and there is also the fricative noise
originates at different articulatory constriction, so you can hear the difference between
those noises and they have voiced and voiceless cognates meaning pairs. So we go /s,z,f,v,
ʃ, Ʒ/. You hear the difference?
Okay, those are some fricatives. Now, how is a fricative being produced? The air stream can be
phonated or unphonated, voiced or voiceless, right.
When that airstream comes through the constriction of the vocal tract the
constriction is brought by two articulators, the two articulaotrs can be your
teeth and your lips so /f/ or your tongue at your alveolar ridge, those are the two articulators /s/ or your tongue at palate /ʃ/.
Okay, the constriction of the vocal track has bought by two articulators. The key
important thing is your velopharyngeal port is closed.
Unlike the nasals where your velopharyngeal port is open because the air has to pass
through your nose, here we do not want to pass any air through the nose. So for
example, if you place your finger right beneath your nose and you go "ssss", you're
technically not supposed feel any air coming through your nose okay, so your
velopharyngeal port is closed. The air stream should be strong, the
constriction should be in narrow and it makes air flow turbulent and creating
friction may get aperiodic vibrations. Hold onto that thought for a second because I'm
gonna come back and talk about certain characteristics between mixed periodic
and aperiodic when we have some voiced fricatives. Alright, so here we go
again, how it is being produced? The air stream is phonated or unphonated, right because you
can have voiced or voiceless sounds. When that air stream comes through your vocal tract
the constriction in the vocal tract is brought by two articulators so for
your /f/ it's your teeth and lips, linguadental, /f/ yeah linguadental is /f/, okay. Between your teeth and your lips can be
ther /f/ and then you have the alveolar which is your
tongue to your alveolar ridge, so it's the /s/ and then you have the tongue to your palate which is the /ʃ/
Okay, it's brought through two articulators. Your velopharyngeal port has to closed, right,
because you need the airstream to pass only through your oral cavity, you don't want to go
through your nose. The air stream should be strong the constriction should be narrow, it makes
airflow turbulent and hence with the fricatives you have aperiodic
vibrations coming through your oral cavity but when it becomes the voiced sound,
remember /z, Ʒ, and v/
these are voiced fricatives which has periodicity. It's periodic at the level
of the vocal folds because the vocal folds are vibrating and then it's aperiodic at
the level of the vocal tract because of the turbulent constriction, so those
becomes mixed aperiodic and periodic voiced sounds, I mean sounds. The
acoustic cues that we have in fricatives are energy in the high-frequency region.
Again remember there is little or no formants so it's not a resonant sound,
the only thing that I want you know is this,
that's going to be a major cue is the energy in the high-frequency region.
Alright what I'm gonna do is I'm gonna stop here because I need to I'm gonna
let you go over all of the concepts that we have so far and then I'll come back
and talk in more detail about the acoustic cues for your /s/ and /Ʒ/ sounds and how
to differentiate between those, okay. Alright, so we've done the nasals, we've
started with the fricatives. Nasals are murmur, acoustic cues, antiresonance, murmur is between 200
to 300 Hz and seen on the spectrogram, antiresonance is varied between 500 to
2500 Hz and antiresonce are not seen on the spectrogram. Fricatives all we've only
talked about how was being produced and the main cue is gonna be energy in high-frequency
region and no formants. Okay, we will continue back with the fricatives
the next lecture.