JCPSLP vol 14 no 3 2012

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JCPSLP Volume 14, Number 3 2012 133
Participant 3
Vocal quality
Duration of sustained ah was considerably reduced,
suggestive of reduced respiratory-phonatory control and
more rapid loss of air with breathiness. Average f0,
standard deviation of f0, jitter and shimmer were within the
normal range on ah production. HNR was reduced relative
to the threshold, suggestive of hoarseness, although the
participant was perceived to have a breathy rather than
hoarse quality.
Speech rate and prosody
The perception of slowed speech rate was upheld with
slowed repetition rates on AMR and SMR tasks and
particularly for connected speech, compared to normal.
P3’s PVI_Dur was significantly reduced compared to the
control participant, suggesting equalisation of stress in
connected speech, despite this not being reported
perceptually. However, the participant was perceived to
have vowel and consonant prolongations, which may
threshold for pathological voice, and this was consistent
with the absence of any perception of vocal roughness. The
value for shimmer was close to the conservative threshold
supporting the perception of loudness variations and vocal
tremulousness. HNR was slightly below the recommended
threshold, indicative of mild vocal hoarseness although this
was not noted in the perceptual evaluation.
Speech rate and prosody
Performance on AMR and SMR tasks was characteristic of
ataxic dysarthria with fewer syllables per second and the
perception of slowed speech rate and disrupted rhythm.
Speech rate was considerably reduced in the reading task,
compared to healthy adults.
The predominant prosodic features perceived in P2’s
speech were equal and excess stress, irregular pitch
breaks, and higher than normal loudness variation. This
participant showed the lowest PVI_Dur value, significantly
lower than the control, which is consistent with equal and
excess stress. PVI_f0 and PVI_dB were slightly elevated,
but not significantly different to the control speaker.
Table 3. Results of acoustic analyses with normative comparisons
Measures P1 – M
(Spastic)
Comparison data P2 – F
(Ataxic)
Comparison data P3 – M
(Flaccid)
Comparison data
Vocal quality
Sustained /a/
Average duration (sec)1 14.2 25.9 12.76 21.3 9.53 25.9
Average f0 2 174.0 145.2
Range: 121.8–168.6
256.5 243.9
Range: 216.5–271.4
156.2 145.2
Range: 121.8–168.6
Standard deviation f0 2 1.2 1.3
Range: 0.7–2.0
11.4 2.7
Range: 0.6–4.8
2.4 1.3
Range: 0.7–2.0
Jitter (local) 2 0.54 ≤1.04% 0.55 ≤1.04% 0.64 ≤1.04%
Shimmer (local) 2 2.87 ≤3.81% 3.74 ≤3.81% 2.76 ≤3.81%
Harmonic-to-noise ratio 2 19.47 >20 19.38 >20 19.96 >20
Speech rate and prosody
Alternating Motion Rate tasks 3
‘pa’ repetition (syll/sec) 3.4 Range: 4.5–7.5 2.5 Range: 4.6–8.6 2.5 Range: 4.5–7.5
‘ta’ repetition (syll/sec) 3.3 Range: 4.4–8.2 2.3 Range: 4.3–8.5 2.5 Range: 4.4–8.2
‘ka’ repetition (syll/sec) 3.6 Range: 4.4–7.5 2.0 Range: 4.3–7.9 2.3 Range: 4.4–7.5
Sequential Motion Rate task 3
‘pataka’ repetition (syll/sec) 3.6 Range: 4.8–7.2 3.4 Range: 4.8–7.2 2.8 Range: 4.8 – 2.0
Connected speech (Grandfather)
Speech rate (syll/sec) 4 2.1 4.3 (± 0.5) 1.4 4.3 (± 0.5) 0.7 4.3 (± 0.5)
Pairwise Variability Indices 5
duration 29.3** 46.6 25.8** 47.8 28.5** 58.4
f0 10.4 9.4 9.1 7.0 4.7** 7.3
dB 4.5 3.8 4.5 3.1 3.1** 5.6
Note: Underline = values outside normal range
1 Colton et al. (2006)
2 Norms from Multi-Dimensional Voice Program (MDVP; Kay PENTAX, Lincoln Park, USA): MDVP Jitt and Shim cut-off values are used, but are
conservative here as the Jitter and Shimmer measures in PRAAT are less influenced by noise
html; Maryn et al., 2009)
3 Kent (1997)
4 Tauroza & Allison (1990)
5 Comparison data from matched controls; controls’ duration values are comparable to Low et al. (2000) for “reduced vowel set” sentences;
**p<0.01 and *p<0.05 for Wilcoxin Matched Pairs tests between participant and matched control.