Vic Firth SIH1 Stereo Isolation Drummers Headphones are designed to protect
  musicians from the high sound levels associated with their instruments.

The SIH1 Isolation Headphones reduce outside noise by up to 24dB, which means you won't need to crank the headphone level to hear your monitor mix. That means less ear fatigue and damage over long periods. And because they're comfortable to wear and built to last, any live show or studio session is a great place to use the Vic Firth SIH1 isolation headphones.

The SIH1 reduces overall noise levels by 24 decibels and features high quality
  stereo headphones. Unlike non-isolation headsets, where musicians typically
  crank the volume to very high and potentially damaging sound levels in order
  to hear the music clearly, the SIH1 reduces ambient noise from the instruments.
  This allows the musician to play along with the recorded music or monitor other
  performers in a live situation at comfortable and safe sound levels.

Vic Firth SIH1 Specifications

Speaker Type: 50.m/m Dynamic Speaker Mylarcon
  Magnet: NFB 15x1.5 Four-Hole Style (50u)
  Sound Pressure Level:110.Db +/- 3dB (1mw at 1kHZ)
  Rated Input Power: 30.mw
  Maximum Input Power: 100.mw
  Impedance: 250-ohm +/- 15%
  Frequency Response: 20Hz - 20kHz
  Cord: 12.5 F coil cord with 3.5 stereo plug (1/4" and 1/8" plugs
  included)
  Comfort Features: Automatically self-aligning for perfect fit and protection.
  Broad foam cushions provide maximum comfort.