Everyday Noises Can Be Harmful to Hearing
It is generally well known that noise levels at rock concerts can cause permanent hearing damage in humans. But there are many other noises around in everyday life that can be just as harmful as the loudest rock music.
This is the conclusion of research conducted by Dr. Kenneth O. Jones, assistant professor of communicative habilitation at Brigham Young University.
Dr. Jones has run tests on teenagers with noise-induced hearing losses comparable to those of men who have spent a lifetime working in noisy factories. Rock concerts and stereos turned up full blast account for some of these teenage hearing losses but they are not the only villains. For instance, a snowmobile produces a sound pressure level averaging 108 decibels on the A measuring scale (dBA), while a rock concert averages 102 dBA, Dr. Jones stated. The U.S. Occupation Safety and Health Act of 1970 specifies that no one should be exposed to 108 dBA for more than 45 minutes or 102 dBA for more than 90 minutes.
“If you attend one rock dance for a couple of hours or ride a snowmobile for an hour, you can lose a little bit of your hearing permanently,” Professor Jones warned.
He pointed out that strict adherence to the Safety and Health Act is supposed to protect 50 percent of the population. This means that many people sustain a certain amount of permanent hearing loss when exposed to noises below the specified safe limits.
The general public needs to become aware that many sounds encountered in daily life can cause permanent hearing damage. For example, a table saw will average 100 dBA; a power lawn mower, 95; and a kitchen blender, 91. Safe exposures for each of these levels, according to federal standards, are two, four, and eight hours respectively.
“Basketball games at BYU have been measured as high as 105 dBA,” Dr. Jones said. “The level doesn’t remain constant at 105 dBA, but if it did for more than an hour, we would be violating the Safety and Health Act.”
Dr. Jones and his assistants have found hearing losses caused by noises from gunfire, dentist drills, helicopters, oil well derricks, television and stereo sets, and power tools, among other things.
Unfortunately, noise-induced hearing losses are not easily corrected by hearing aids, and once sustained, they remain for life, Dr. Jones explained. The ears become insensitive to the higher hearing range frequencies, making it difficult to distinguish the soft “th,” “s” and “wh” sounds.
Paradoxically, people with noise-induced hearing losses are actually bothered by noise. Those who insist on listening to loud music will enjoy it less and less as time goes by.
Since noise-induced hearing losses occur slowly, they are difficult to detect at first. But one sign of possible damage is a ringing in the ears after being exposed to harsh, sharp, or loud sounds.
Since noise-induced hearing losses are permanent and are hard to correct with hearing aids, the key to the problem is to prevent the losses in the first place. This means eliminating the noise if possible, and if that can’t be done, the exposed person should be equipped with protective devices, such as specially made ear plugs, ear cups, or sound helmets.
As for eliminating or reducing the noise, much could be done by manufacturers if they would equip their machinery with proper mufflers or other sound-deadening devices, Dr. Jones says. “These things can be done and they will be done as the public becomes aware of what is happening in the world of noise pollution and demands that something be done.”
Canal Discoveries Indicate Advanced Civilization
Excavations by a team of Brigham Young University archaeologists on the Yucatan Peninsula indicate that an early pre-Mayan culture had an advanced knowledge of engineering and intensive farming more than 2,000 years ago.
A network of some 30 canals and over 25 man-made, large-scale reservoirs has been discovered beneath the jungle overgrowth at the ruins of Edzna, about 30 miles west of Campeche, Mexico. Artifacts emerging from pits and surface collections date construction of the works sometime between 400 B.C. and A.D. 100, during what archaeologists call the late pre-classical period.
Dr. Ray T. Matheny, associate professor of archaeology at BYU, says the ancient builders must have had engineering know-how, as indicated by their ability to determine descent of grades. Their canals still drain water from the outlying jungle areas and divert it into the complex of reservoirs.
According to Dr. Matheny, “The deep rich soils, which are rare on the Yucatan Peninsula, and the possible use of canals for pottery watering suggest intensive agricultural practices not known among the Mayan peoples today.”
Watering crops with supplemental moisture is a departure from the well-known “milpa” or “slash and burn” primitive system of land use employed by the Mayan Indians, which archaeologists have theorized eventually depleted the land and led to the decline of the Mayan civilization some time around A.D. 900.
The canals provided drainage for the water-logged clay soils in the area, further enhancing its agricultural potential. Such soils without drainage are too wet in the rainy seasons and bake to become untillable during dry spells. Use of supplemental water would have allowed the people to grow crops year around.
The canals radiate “like the spokes of a wheel” from a large Mayan pyramid known as Cinco Pisos, which was discovered in 1927. The pyramid dates back between A.D. 700 and 900, during the peak of the late classic period.
Academic Grades Not Related to Family Size
Fact: Members of the Church have larger families than the average. Theory: Children from large families don’t do as well in school as children from small families. Therefore, Mormon children don’t do as well in school as their fellow students who are not members of the Church.
Family size has little to do with how well children do in school, according to the work of a team of three Brigham Young University researchers, Phillip R. Kunz, Evan T. Peterson, and Lynn W. Davis.
The research team examined the relationships of family size, grades, religion, and social class for 5,321 high school students from 27 schools in different sections of the United States.
The research disagrees with a commonly held notion that parents with large families (five or more children) do not have enough time to spend with their children and therefore their children are academically slower than their fellow students.
When the researchers studied the correlation between Church membership and grades, they found that in nearly every instance members of the Church averaged higher grades than their peers.
The survey also indicated that in almost every case the academic achievement of Latter-day Saint girls was not only higher than that of LDS boys, but also higher than that of non-LDS boys and girls.
The research team suggested that members of the Church spend considerable time with individual children and that family size does not seriously limit the amount of time a child spends with his parents. Large families also give children a chance to learn and develop in association with other children.