Some 700,000 Israelis - including one third of those over 65 - suffer from inadequate hearing. Many of them have difficulty communicating with their environment and suffer from a significantly lower quality of life. But a significant number don't seek help for their disability because of embarrassment. National Hearing Week is being marked starting Tuesday for the fourth time. The activities, initiated by the Health Ministry with a large variety of other institutions including the Israel Defense Forces, National Insurance Institute, universities and hospitals, are aimed at increasing awareness of hearing disability and promoting prevention, early diagnosis and treatment. Prevention by avoiding loud noises is regarded as vital, as it eliminates the need for diagnosis and treatment. High-decibel noise also causes sleep problems, headaches, irritability, tiredness and difficulty in concentration. If a person gets used to loud noises that don't bother him, it is a sign that his hearing ability has already declined. The Home Front Command has given 40 beepers to the deaf and hearing disabled in Sderot who are unable to hear the sirens warning of an impending Kassam rocket attack. Another 100 have been donated by the Jewish Agency, and the Home Command is programming them for residents of other settlements near Gaza. Their distribution has been delayed somewhat, since each settlement requires unique programming. Clalit Health Services will operate an open phone line on Tuesday between 1 and 4 p.m., with questions about hearing problems to be fielded by otolaryngologists and clinical communications specialists from the health fund. Call *2700 from any phone. Clalit advises people to stay away from noisy places. If they have to be in one, as at a wedding with a noisy band, leave the premises for a rest for time to time. Bring earplugs. Make sure you are not sitting close to the audio speakers in a hall. Don't operate several noisy electric devices at once. Don't put the volume of earphone devices high. The Tel Aviv Fairgrounds will offer a central National Hearing Week event on Thursday between 11 a.m. and 5 p.m.. Information booklets and earplugs will be handed out at shopping malls around the country. Educational institutions will explain the dangers of excess noise to schoolchildren. The Bekol voluntary organization will offer information and support by phone at (03) 5257001 or fax (03) 5257004. More information can be obtained from the Web site at www.hearing.org.il.