Ivergård T B, Nicholl A G
Am Ind Hyg Assoc J. 1976 Mar;37(3):139-42. doi: 10.1080/0002889768507436.
Ten different common muff-type ear defenders were tested by 50 potential users for comfort and ease of use. Results showed short-term (3 min) impressions to be a good predictor of long-term comfort; defenders were ranked for comfort and pointers are given for important design features. Only comfortable ear defenders will be worn properly.
