Ghetto blaster was the nickname given by people on late 20th century Earth to a large boom box equipped with AM/FM radio and a casette recorder. Some owners of these electronic devices would decorate them with stickers.
In 1986, a punker played the song "I Hate You" loudly on a ghetto blaster. At the time, he was on a bus traveling northbound on the Golden Gate Bridge. After ignoring Kirk asking him asked to lower the volume, he was nerve pinched by Spock. When the punker's head landed on the machine, he inadvertently turned it off. (Star Trek IV: The Voyage Home)