CS 551/651:Structure of Spoken Language

Spectrogram Reading: Approximants

John-Paul HosomFall 2010

Spectrogram Reading: Liquids and Glides (Approximants)

• There are 4 approximants and 1 glottal phoneme:approximants: /w/, /y/, /r/, and /l/glottal phoneme: /h/

• Approximants have slow rate of articulatory movement, resulting in slowly-changing formant patterns

• /w/ and /y/ can be viewed as extreme production of vowels /uw/ and /iy/

• /l/ is made with tongue tip touching alveolar ridge. When /l/ is followed by a vowel, there is often a visible discontinuity in the spectrum corresponding to the release and an abrupt increase in energy. When /l/ is post-vocalic, no discontinuity and a gradual decrease in energy.

• /r/ has F3 < 2000 Hz, F2 typically close to F3

Spectrogram Reading: Liquids and Glides (Approximants)

• /h/ is usually unvoiced and has formant structure. Voiced /h/ distinguishable by formant structure and voicing with high noise levels in higher frequencies and lower energy relative to surrounding vowels. /h/ often has weak F1 region

• /w/ has very low F1 and F2 (both < 1000 Hz), fairly low F3 if visible. F3 and higher formants often not visible. Also, in transition to neighboring vowel, F3 is “delayed”, in other words visible only after F1 and F2 are visible in the vowel.Also, since /w/ is labial, all formant of neighboring vowel should drop toward the /w/ (except for F3 in /er/, which has even lower frequency)

Spectrogram Reading: Liquids and Glides (Approximants)

• /l/ has low F1 and F2, very high F3 (opposite of /r/); energy in higher frequencies often noticeable

• Post-vocalic /l/ often not fully articulated; seen in dropping of F1 and F2 and rise in F3, with gradual decrease in overall energy

F1=500F2=1000

F3=3000

NOTE: /uh/ has average F1=450, F2=1030, F3=2380

Spectrogram Reading: Liquids and Glides (Approximants)

• /y/ is extreme form of /iy/; F1 is extremely low, F2 and especially F3, F4 are extremely high; if /y/ is adjacent to back vowel or /l/, can see “crossing” of formants (e.g. /yu/)

Spectrogram Reading: Liquids and Glides (Approximants)

• Coarticulation with approximants can have severe effecton neighboring vowels…

Spectrogram Reading: Liquids and Glides (Approximants)

/w iy y i:/

/r iy l i: h i:/

/w ah y ah/

/r ah l ah h ah/

/w aa y aa/

/r aa l aa h aa/

/iy w iy iy y iy/

/iy r iy iy l iy iy h iy/

/ah w ah ah y ah/

/ah r ah ah l ah ah h ah/

/aa w aa aa y aa/

/aa r aa aa l aa aa h aa/

/iy r iy l/

/ah r ah l/

/aa r aa l/