Shepherd's whistle
They are also produced commercially. Simple whistles may cost less than 1 USD in bulk; expensive ones may be quite ornate. They are commonly made of plastic, aluminum, stainless steel, silver, brass, titanium, Corian, jade, buffalo horn and other materials.
British Wireless for the Blind Fund
Following the appeal, the first 100 crystal radio sets made by Burne-Jones & Co Ltd were issued to blind people at a cost of 31/6d per set. Headphones cost 7/3d a pair. Winston Churchill made another Appeal at Christmas in 1930 asking for a further £20,000 to provide another 10,000 people with radios. He reminded listeners that it had been a year since he first appealed for the cause and wondered whether the year had gone quickly for blind listeners. He said that wireless brought the blind each night a pageant before their mind's eye. "That mysterious lamp of inner conscientiousness will be continually fed by your unfailing care. The blind will hear, and by hearing, see." By 1931, £37,000 had been raised and 17,000 radio sets provided to blind listeners. In 1932 Lord Snowdon made the appeal, asking for donations to provide 2,000 more blind people with sets. James Ramsay MacDonald, Labour Prime Minister between 1931 - 1935, continued the tradition and appealed for additional funds on behalf of British Wireless for the Blind Fund from his home in Lossiemouth on Christmas Day 1933.