Audiological screening of Amerindians of the Suriname rainforest

Audiological screening tests were conducted among a remote, relatively noise-free population of Amerindians in the deep rainforests of Surinam, South America. These preliminary tests, the initial step in a planned long-term study, were the first such examinations on these people, and were intended to examine the overall audiological health of the population as a function of age and sex. Audiological testing of this non-technological population was more challenging than conventional test situations in modern industrial societies because the tests were hampered by a variety of extraneous factors. The results from a sample of the population showed a range of hearing impairments similar to that seen in modern industrial societies, including conductive, mixed, and sensorineural hearing losses. Also, hearing sensitivity was found to deteriorate with age in both females and males, particularly at the higher frequencies (2, 4, and 8 kHz). This deterioration was slightly greater for males, who as hunter-gatherers regularly use shotguns for hunting. Impact noise from hunting guns is the only source of intense noise to which the Amerindian population is exposed with any regularity. The diet of the Amerindians includes as the main carbohydrate staple the manioc cassava, which has also been linked to sensorineural hearing loss in some populations.