These effects are high-quality, first generation copies of original nitrate optical sound effects from the 1930s & 40s created for Hollywood studios. They were collected by a prominent sound editor who worked in the industry for 44 years. The fragile optical elements were donated to USC, and transferred to tape by USC Cinema students in the early 1970s. I have digitized them for preservation, but they have not been restored. You may want to use some noise reduction. Or you may embrace the noise of history.