Distant Speech Detection
Victor N. Sorokin · Acoustical Physics · 2023
The article studies the amplitude and phase responses of speech signals recorded at different distances from the speaker by various types of microphones in free space and in a closed room. The ratios of the average energy of the amplitude spectrum in different frequency ranges and the average slope of the linear phase component show differences for a syllable recorded near a microphone and the same syllable recorded distantly and again reproduced near the microphone. The greatest difference is observed in the average-energy ratios in the frequency ranges of 0–1 and 1–8, as well as 3–4 and 4–6 kHz. The slope of the linear component is calculated in the 4–8 kHz range. The degree of differentiation depends on the vowel sound.