March 2010

Surround Sound by ReSound and Spatial HearingJohn Nelson, Ph.D.
Amplification can provide increased audibility for individuals with hearing losses and results in better speech understanding.  While this is a critical part of successful amplification, many users report that the amplified sounds are unnatural.  One aspect of the unnatural sound experience is not being able to localize where sounds are coming from.  The ability to localize sounds provides the listener with spatial awareness. 
 
Imagine listening to a movie on an older single-loudspeaker television compared to a movie on a surround-sound television system.  In the television-only situation, the sounds are audible but everything comes from the direction of the television.  In the surround-sound television system, the multiple loudspeakers deliver sounds from different directions. 
 
Our ears are able to detect very small differences in loudness and arrival time between the two ears.  These differences are also frequency (or pitch) specific.  These cues provide spatial awareness.  Unfortunately, many hearing instruments distort or eliminate these acoustical cues.  This makes it difficult and sometimes impossible for the listener to determine the location from which a sound originates.  Surround sound by ReSound preserves necessary acoustical cues for the listener to maintain spatial awareness. It allows individuals to feel that they are included in the listening situation or conversation instead of just hearing from the sidelines. 
 
The link below will take you to a sound demonstration of Surround Sound by ReSound with bilateral amplification.  To hear the differences in this sound demonstration, it is critical to listen in stereo through headphones.  The speaker will do a listening check to ensure the headphones are on the correct ears.