Comparison of long‐term average speech spectrum at ear‐level and standard recording positions

Abstract

The long‐term average speech spectrum (LTASS) was obtained from ten male and ten female talkers for two microphone positions. Dual channel recordings of speech were recorded and played back for spectrum analysis. One channel recorded the speech signal obtained from a microphone placed 30 cm directly in front of the talker, while the second channel recorded the speech signal obtained from a microphone placed at the talker's ear. A spectrum analyzer (BK type 4132) was used to compute the overall levels and 1/3‐octave‐band levels. The analyses indicated significant differences in overall and the 1/3‐octave‐band levels between the two recording positions. The mean overall level at the position of the ear was approximately 6 dB higher than the overall level at the standard recording position. Also, 1/3‐octave‐band analyses indicated that the ear‐level LTASS consisted of more low‐frequency energy and less high‐frequency energy than the LTASS recorded at the standard position. The implications of these results for hearing aid selection will be addressed.