When the dialog is buried within an acoustic scene with lots of other noises, such as traffic, or mood music, it quickly becomes unintelligible to those of us with a hearing loss. Turning up the volume does no good, as all the sounds just get louder, while the dialog remains unintelligible.
What research and science tells us about hearing and understanding in noise, seems to be totally lost on many of the directors and sound engineers creating the content we all watch on Netflix, cable, or broadcast TV.
The difference just a couple of decibels can make in understanding in noise is highlighted by the incredible beamforming done by today’s high end digital hearing aids, as they constantly monitor their listener’s sound environments, monitoring, locating and assigning relative value to each sound within the environment and then making logical decisions about which signals are the most important to the listener and amplifying them, over the rest.
These incredible instruments work by analysing all the sounds surrounding the listener, then separating them by location and classification, (speech, noise, or speech in noise) and finally deciding which ones are the most likely to be important to their listener.
Yet, when all of the sounds associated with a movie are being broadcast through two channels, as is done in a stereo broadcast, even the best noise reduction hearing aids fail, as there is no way to extract the dialog in real time when it is buried within all the garbage associated with the background sounds that have been mixed in for director’s effect and mood.
So while I laud NPR for the great piece for their highlighting of the issue of hearing loss and dementia, they could have given some attention to the actual underlying reason why so many of us have trouble understanding today’s entertainment, that all important Signal/Noise Ratio.