This corpus comprises 1,500 entries uttered by 200 speakers of different dialects, ages and various educational levels (87 males and 113 females), recorded over 4 channels (Mic1: SHURE SM58; Mic2: ANC-700 Head-mounted; Mic3: TELEX M-60; Mic4: ACOUSTIC MAGIC). The database comprises 6,000 digit strings per channel. Speech samples are stored as a sequence of 16-bit 22.05kHz WAV for 11.5 hours of speech per channel. The total capacity of the data is 6.82 Gb. Each speaker read 30 items. Text files are stored in Unicode format. All data have been proofread manually. The transcriptions include non-speech markers (background noise, background speech, speaker sounds) as well as markers for mispronunciation, channel distortions, words left-out and duplicates. The corpus aims to be applied to the testing and telephone natural speech recognition system.