In-ear Monitor (IEM, universal IEM, In-ear headphones) is a small size earphone, worn by inserting deeply into the ear canal of the listener, helping enhance the sound insulation level with the outside environment, and carrying to give users high sound quality. IEM is a specialized product for sound engineers, musicians, singers, or audiophiles. IEM headphones help singers can clearly hear the sound of the instruments, the vocals I need to hear more while reducing the sound on stage.
IEM headphones also have the function of filtering environmental sounds due to the design that fits the ear canal. Therefore, in some music stages, there is also a system of multiple microphones so that singers can hear certain audience responses through IEM headphones. Nowadays, IEM has become more popular and there are a lot of products for ordinary users.
IEM for EDM, DJ, Dance music: Sennheiser MM30g and IE80
IEM for Pop music: SoundMAGIC E10s, Sony MH1C
IEM for Classic music: Grado GR8i