Hearing in Dual Mono vs. True Stereo
by Neil Bauman, Ph.D.
A number of hard of hearing people have asked me to explain exactly what the difference is between hearing dual mono sound and hearing stereo sound.
With mono sound, there is only one microphone involved in picking up the sounds. Since there is only one microphone picking up the sound, there is only one sound amplifier, and one sound heard in the earphones.If you are wearing dual earphones, you hear exactly the same sound in each ear. This is dual mono.
With stereo, there are two microphones picking up the sounds, Since there are two microphones picking up separate sounds (with some overlapping to be sure), there are two sound amplifiers and if you are listening to a stereo device and wearing stereo earphones, you will hear different sounds in each ear. This is true stereo sound.
Stereo is what gives sound directionality–sounds seem to be coming from one side or the other or in front of you.Mono sound has no directionality associated with it. It is just “there.”
Most assistive devices are mono devices, so you will hear the same sound in both ears. However,in the hearing world, most audio devices–radios, TVs, DVDs, CDs, iPods, MP3 players, etc are all stereo devices.
If you want to hear true stereo sound, you need to learn how to couple your hearing aids to the various portable stereo devices. The article, “Using T-Coils to Couple Your Hearing Aids to Various Audio Devices” explains what you need, and how to do this.
This article also explains what you need to do if you want to use a mono coupling device (such as a neckloop) to couple to a stereo system so you don’t accidentally short out one of the stereo amplifiers.