Corpus of European Portuguese Stops


A corpus of 54 European Portuguese real words containing /p, b, t, d, k, g/ was designed to study the temporal and spectral characteristics of stop consonants.

Corpus 1 and 2

The corpus contained an equal number (eighteen) of words with stops in: initial position, followed by the vowels /a/, /i/ and /u/; medial position, preceded by the vowels /a/, /i/ and /u/ and followed by the vowel /ɐ/; final position, preceded by the vowels /ɔ/ and /a/. The words were produced without any context (Corpus 1) and within the frame sentence "Diga,... por favor." (Corpus 2).

Recording Method

The subjects were six native speakers of European Portuguese, three men LJ, HR and PA (aged: 25 to 34) and three women ML, IM and SC (aged: 24 to 42), all without any speech, language or hearing problems. Subjects LJ, HR, ML and IM are from the city of Aveiro (at the centre of Portugal) and Subjects PA and SC are from Porto (in the north of Portugal).

The corpus was recorded using a Philips SBC ME 400 unidirectional condenser microphone located 20 cm in front of the subject's mouth. A laryngograph signal (Lx) was also collected using a laryngograph processor (model EG-PC3 produced by Tiger DRS, Inc., USA). The acoustic and Lx signals were pre-amplified (Rane MS 1-b) and recorded with a Sony PCM-R300 DAT recorder, each with 16 bits and a sampling frequency of 48 kHz.

Segmentation and Annotation Method

The corpus was manually segmented with Adobe Audition. The words were then analyzed using Speech Filling System (SFS) and the following acoustic events were annotated:

  1. The beginning of preceding vowel (IV1) was defined as the instant in time at which the second formant intensity becomes characteristic for a vowel.
  2. The end of preceding vowel and beginning of closure (IO) was marked where the second formant was no longer visible.
  3. The beginning of prevoicing (IPV) was defined as the instant in time at which evidence of vocal fold vibration could be observed both in the acoustic and Lx signals.
  4. The voice offset (FV) was marked at the point where the vocal folds ceased to vibrate, as can be seen in the Lx signal in Figure 1 (the periodic signal ends).
  5. The end of prevoicing (FPV) was defined as the instant in time where the burst started.
  6. The end of closure and the beginning of the release (IR) was defined by a sudden peak in the waveform and as a vertical bar in the spectrogram. When there were multiple bursts, the one with the highest intensity was chosen.
  7. The end of release and beginning of following vowel (FR) was marked where the second formant amplitude reached typical values for a vowel.
  8. The end of the following vowel (FV2) was set where the second formant was no longer visible.
In the annotation files we also registered the position in word (initial (0), medial (1) and final (2)) and the type of voicing according to criteria defined by Jesus and Shadle (2002):

Corpora Documentation and Distribution

Complete listing of all recorded material can be found in the M.Sc. Thesis by Lousada (2006).

The corpora can be stored in one CD-ROM that contains the following data:

When the annotations points 1 to 8 were not observed their value was set to zero.

Last updated 25/6/2007
Luis Miguel Teixeira de Jesus

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