The HHIA, for example, is a 25-item questionnaire that asks both social and emotional-specific questions such as: Does a hearing problem cause you to avoid groups of people?" (social) and "Does a hearing problem cause you to feel frustrated when talking to members of your family?" (emotional). Response options are yes, no and sometimes. A greater score indicates greater perceived handicap. Cause
The ear can be exposed to short periods of sound in excess of 120 dB without permanent harm — albeit with discomfort and possibly pain; but long term exposure to sound levels over 85 dB(A) can cause permanent hearing loss.There are two basic types of NIHL:

NIHL caused by acoustic trauma and
gradually developing NIHL. Acute acoustic trauma
NIHL caused by acute acoustic trauma refers to permanent cochlear damage from a one-time exposure to excessive sound pressure. This form of NIHL commonly results from exposure to high-intensity sounds such as explosions, gunfire, a large drum hit loudly, and firecrackers. According to one US study, excessive noise levels in cinemas are sufficiently brief that movie-goers do not experience hearing loss. Perceived harmfulness vs. actual harmfulness
The discomfort threshold is the loudness level from which a sound starts to be felt as too loud and thus painful by an individual. Industry workers tend to have a higher discomfort threshold (i.e. the sounds must be louder to feel painful than for non-industry workers), but the sound is just as harmful to their ears.
Sucrose is simply hydrolyzed into an invert sugar syrup, which contains about 50% fructose. In both cases, the syrups are chromatographically purified to contain 90–95% fructose. The fructose is then hydrogenated over a nickel catalyst into a mixture of isomers sorbitol and mannitol. Yield is typically 50%:50%, although slightly alkaline reaction conditions can slightly increase mannitol yields. Biosyntheses
Mannitol is one of the most abundant energy and carbon storage molecules in nature, produced by a plethora of organisms, including bacteria, yeasts, fungi, algae, lichens, and many plants. Fermentation by microorganisms is an alternative to the traditional industrial synthesis. A fructose to mannitol metabolic pathway, known as the mannitol cycle in fungi, has been discovered in a type of red algae (Caloglossa leprieurii), and it is highly possible that other microorganisms employ similar such pathways. A class of lactic acid bacteria, labeled heterofermentive because of their multiple fermentation pathways, convert either three fructose molecules or two fructose and one glucose molecule into two mannitol molecules, and one molecule each of lactic acid, acetic acid, and carbon dioxide. Feedstock syrups containing medium to large concentrations of fructose (for example, cashew apple juice, containing 55% fructose: 45% glucose) can produce yields 200 g (7.1 oz) mannitol per liter of feedstock. Further research is being conducted, studying ways to engineer even more efficient mannitol pathways in lactic acid bacteria, as well as the use of other microorganisms such as yeast and E. coli in mannitol production.