SPIRE VCV is a database of speech production, which includes simultaneous acoustic and electromagnetic articulography data collected from speakers of non-native/Indian English.
Stimuli comprises of non-sense symmetrical VCV (Vowel-Consonant-Vowel) utterances as part of the sentence "speak VCV today" in three different speaking rates: slow, normal, and fast with 3 repetitions each.
The VCV utterances consist of the combination of 17 consonant sounds namely: C = { /b/, /ch/, /d/, /f/, /g/, /jh/, /k/, /l/, /m/, /n/, /ng/, /p/, /r/, /s/, /t/, /v/, /z/ }
And 5 vowel sounds: V = { /a/, /e/, /i/, /o/, /u/ }
Ten non-native English speakers: 5 female and 5 male in the age range of 18 to 27 years with no speech related disorders.
Recordings were made in the sound damped studio at the SPIRE Labs speech recording facility. Acoustic and articulatory data were recorded directly to the computer and carefully synchronized.
Articulatory movements were recorded using a 3D Electromagnetic Articulograph. (EMA) AG501.
A t.bone EM9600 shotgun unidirectional electret condenser microphone was placed near the subject to record the audio data synchronously with the articulatory data.
Audio:
originally recorded at 48 kHz then downsampled to 16 kHz.
Articulatory data:
Sampled at 250 Hz.
A 10th-order lowpass Chebyshev Type II filter with 40Hz cut-off frequency and 40 dB of stopband attenuation was used to low-pass filter the articulatory movement recording to remove the high-frequency noise resulting from EMA measurement error.
Sensor placement
6 sensors were placed on the different speech articulators namely:
Upper Lip
Lower Lip
Jaw
Tongue Tip
Tongue Body
Tongue Dorsum
Sensors were also placed behind the left and right ear for the purpose of head movement correction.
Each of these 6 sensors captures the movements of the articulators in 3D space, resulting in eighteen articulatory features
Instructions to speaker:
All speakers were college going students fluent with reading, writing and speaking English coming from different regions of India with different native language backgrounds.
Speakers were given prior training to increase speaking rate gradually during the main recording.
A GUI produces the stimuli to be uttered on screen and the user pronounces it for each of the three different speaking rates, namely slow, normal/habitual, and fast and three repetitions each.
V-C-V Boundary annotation:
The VCV boundaries were manually annotated by a team of four members.
These boundaries were marked using an in-house built MATLAB annotation tool by observing the wideband spectrogram, the raw waveform and glottal pulses obtained using praat.
For unvoiced consonants: the last glottal pulse in the V1 region was considered for marking the onset of the C region, and the first glottal pulse at the start of V2 region was for considered marking the end of C-region, in tandem with the spectrogram.
For voiced consonants: the spectrogram with the formants and time domain waveform were considered for marking the consonant start and end boundaries.
For ambiguous cases, a unanimous call was then taken for the boundary marking after an internal discussion among the annotators.
Anusuya P, Aravind Illa, P. K. Ghosh,, "A Data Driven Phoneme-Specific Analysis of Articulatory Importance" International Seminar On Speech Production 2020