analogies and his care in avoiding dramatic oratory: "He looked for words that he would use in an informal conversation with one or two of his friends." Eighty percent of the words used were in the thousand most commonly used words in the English language. The radio historian John Dunning wrote that "It was the first time in history that a large segment of the population could listen directly to a chief executive, and the chats are often credited with helping keep Roosevelt's popularity high." Each radio address went through about a dozen drafts. Careful attention was also given to Roosevelt's delivery. When he realized that a slight whistle was audible on the air due to a separation between his two front lower teeth, Roosevelt had a removable bridge made. Roosevelt is regarded as one of the most effective communicators in radio history. Although the fireside chats are often thought of as having been a weekly event, Roosevelt in fact delivered just 31 addresses during his 4,422-day presidency. He resisted those who encouraged him to speak on radio more frequently, as shown in his response to Russell Leffingwell after the address of February 23, 1942: The one thing I dread is that my talks should be so frequent as to lose their effectiveness. ... Every time I talk over the air it means four or five days of long, overtime work in the preparation of what I say. Actually, I cannot afford to take this time away from more vital things. I think we must avoid too much personal leadership—my good friend Winston Churchill has suffered a little from this. Gallery Chronological list of addresses Link to every chat Reception Roosevelt's radio audiences averaged 18 percent during peacetime, and 58 percent during the war. The fireside chats attracted more listeners than the most popular radio shows, which were heard by 30 to 35 percent of the radio audience. Roosevelt's fireside chat of December 29, 1940 was heard by 59 percent of radio listeners. His address of May 27, 1941, was heard by 70 percent of the radio audience. An estimated 62,100,000 people heard Roosevelt's fireside chat on December 9, 1941—two days after the attack on Pearl Harbor—attaining a Hooper rating of 79, the record high for a Presidential address. Approximately 61,365,000 adults tuned on February 23, 1942, for Roosevelt's next fireside chat, in which he outlined the principal purposes of