{n.}, {slang}, {informal} A thin low-quality phonograph recording frequently bound into books and magazines for use as promotional or advertising material; it may have either a spoken or a musical message. * /Don't throw that away; Sue is collecting sound sheets for her market research course./
SOUND SHEET
Meaning of SOUND SHEET in English
Slang English vocab. Английский сленговый словарь. 2012