Self-induced inner-ear technology, which allows and often leads an individual to believe they are singing at an appropriate pitch, speed, tone, and/or volume in a public location or private karaoke room and is adjusted in direct proportion to the amount of alcohol the individual has consumed.
Warning: Sometimes malfunctions and increases dissonances when more than one pair is worn in large group.
Side Note: Usually worn with beer goggles.
A: Did you hear them singing last night at karaoke?
B: Yeah, they must have had their beer-phones on. . . but, they were kinda cute, weren't they?
A: Yeah, but I had on my beer goggles.