This is the 4th pair of wireless phones that I've purchased(actually 5th if you include bluetooth phones which are not reliable at any distance more than a few feet) and they are the only ones that are not noisy. The 900MHz headphones (RCA, Sennheiser and Sony) all produced a kind of raspy hiss that gets louder as the music gets louder. This noise is produced by transmitter/receiver and cannot be improved by adjusting the volume of the input source. The Amphonys are totally clear. The frequency response is good (decent bass) and they require no tuning: worked perfectly right away. The only downside is that they are not rechargeable (require AA batteries at 1.5 volts). My NmH rechargeables don't work. So far, battery life seems real good (they claim 100 hours max). Finally, wireless phones that work!