近年来随着人民生活水平的不断提高，娱乐业也相应发展起来，城镇中卡拉OK厅林立。为追求环境及音l向效果，卡拉OK厅均安装了空调面封闭了窗户；照明使用的小射灯使室内光线暗淡；仅供进出的厅门也挂上了较厚的门帘。由于通风不良和采光较差，使卡拉OK厅中空气混浊，在这种特定 In recent years, with the continuous improvement of people’s living standards, the entertainment industry has also developed accordingly. There are many karaoke bars in the towns. For the pursuit of the environment and the sound l to the effect, karaoke OK hall are installed air-conditioned surface closed the window; lighting using small spotlights indoor light dim; only for access to the hall also hung a thick curtain. Due to poor ventilation and poor lighting, karaoke hall in the air turbidity, in this particular