P values of paired student T-test concerning the differences of the articulatory parameters between the supine (0°) and the upright (80°) body positions in all pitches and pitch groups.

<p>Significant p values (p<0.02) are in bold print.</p><p>P values of paired student T-test concerning the differences of the articulatory parameters between the supine (0°) and the upright (80°) body positions in all pitches and pitch groups.</p

Morphometric Differences of Vocal Tract Articulators in Different Loudness Conditions in Singing

<div><p>Introduction</p><p>Dynamic MRI analysis of phonation has gathered interest in voice and speech physiology. However, there are limited data addressing the extent to which articulation is dependent on loudness.</p><p>Material and Methods</p><p>12 professional singer subjects of different voice classifications were analysed concerning the vocal tract profiles recorded with dynamic real-time MRI with 25fps in different pitch and loudness conditions. The subjects were asked to sing ascending scales on the vowel /a/ in three loudness conditions (comfortable = mf, very soft = pp, very loud = ff, respectively). Furthermore, fundamental frequency and sound pressure level were analysed from the simultaneously recorded optical audio signal after noise cancellation.</p><p>Results</p><p>The data show articulatory differences with respect to changes of both pitch and loudness. Here, lip opening and pharynx width were increased. While the vertical larynx position was rising with pitch it was lower for greater loudness. Especially, the lip opening and pharynx width were more strongly correlated with the sound pressure level than with pitch.</p><p>Conclusion</p><p>For the vowel /a/ loudness has an effect on articulation during singing which should be considered when articulatory vocal tract data are interpreted.</p></div

Waveform (upper row) and audio spectrum (middle row) for the file after the first noise cancellation (Confon, left panel) and after the second noise cancellation (Adobe, right panel).

<p>The waveforms include all three loudness tasks (mf = mezzoforte, pp = pianissimo, ff = fortissimo, respectively). The lowest row shows Long Time Average Spectra (LTAS) for both files, after the first noise cancellation (blue) and the second noise cancellation (red), respectively.</p

Subjects, voice classification and taxonomy according to Bunch and Chapman [61].

<p>Subjects, voice classification and taxonomy according to Bunch and Chapman [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153792#pone.0153792.ref061" target="_blank">61</a>].</p

Representative mid-sagittal vocal tract profiles from a baritone (subject 10) for the different loudness tasks (mf = mezzoforte, upper row, pp = pianissimo middle row and ff = fortissimo, lowest row) for the pitches G3 (196Hz, left), C4 (262Hz, middle) and E4 (330Hz, right), respectively.

<p>Representative mid-sagittal vocal tract profiles from a baritone (subject 10) for the different loudness tasks (mf = mezzoforte, upper row, pp = pianissimo middle row and ff = fortissimo, lowest row) for the pitches G3 (196Hz, left), C4 (262Hz, middle) and E4 (330Hz, right), respectively.</p

Two Positions of a Participant in the G-Scan.

<p>The upright (a) and supine (b) positions of a subject in the G-Scan during measurements are depicted. The head is located in the isocentre of the magnet, in a dedicated 2-channel phased array neck coil. The upper half of the system, containing parts of the permanent magnet and gradient system, is located in front of the head. The individual in this figure gave written informed consent (as outlined in PLOS consent form) to publish these case details.</p

Articulatory parameters and pitch.

<p>Mean values of all articulatory parameters measured (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112405#pone-0112405-g002" target="_blank">Figure 2</a>) for the 15 subjects completing the task. Data points are ordered by fundamental frequency and are plotted on a logarithmic scale. The x-locations of the data points correspond to pitches C3, C4-A4. A double bar indicates the register change from higher modal to falsetto register. Dashed lines refer to the supine position (0°) and solid lines refer to the upright body position (80°).</p