抄録
To examine how the perceptibility of environmental sounds is affected by listening to music through earphones, the hearing thresholds for pure tones presented through a loudspeaker were measured. Under the condition that the listener wore canalphones, thresholds were considerably higher than those under the condition that the listener’s ears were open. When pseudo-music signals were presented through the canalphones at the A-weighted sound pressure level of 70 dB, the hearing threshold at 2 kHz was almost 70 dB higher than the absolute threshold. How environmental noise affects the listener’s comfortable level of music played on portable audio devices was also examined. The mean comfortable listening levels (A-weighted) under a quiet condition were between 65 dB and 69 dB and those under a noisy condition ranged between 73 dB and 76 dB. It was indicated that when listening to music through canalphones at a comfortable level on a busy street, many environmental sounds would be inaudible.
