this was a thing back at the time. if you played the Imaginary Lover at 45 instead of 33 1/3 (album speed) this is what it sounded like.
She was even asked about it at the time and said that she'd heard it and agreed.
Here's a Rolling Stone piece about it at the time in
1978:
http://www.rollingstone.com/music/ne...icked-19780824