There is one more quality control issue that plagues the record making process.
High pitch noise vinyl.
June 15 2016 because there are several possibilities and because brakes are a crucial safety feature it is best to have a pro diagnose noise.
Sometimes is can sound like a buzz or a very high pitched whistle.
When playing records on my turntable they play at a considerably higher pitch than the original recording.
A vinyl record that is even slightly warped or has a hole that.
A high frequency squeal can be caused by many factors.
Vinyl depends on a mechanically driven system and any such system will introduce minute changes in the speed and pitch of playback.