In the picture our customer Mr John Smith ( not real name) has a high frequency hearing loss which is indicative of wear and tear of the cochlea ( hearing nerve) hair cells. The red line is the right ear and blue left. The vertical axis shows the lowest sound in decibels that Mr Smith can hear at a given frequency ( the horizontal axis). EG at 6000 Hz the lowest sound Mr Smith can hear is 90 db on the right side. At 1000Hz for instance on the left his hearing threshold is 30db.
Whilst there is no universally accepted definition of normal hearing, to hear clearly in a group, in the presence of background noise or even films / dramas etc on TV you would need a threshold down no further than 10-15db.
Mr Smith’s hearing aids would be programmed as per the audiogram. The hearing aid would sample the input sounds for their frequency and loudness and then apply the necessary amplification to enable Mr Smith to hear that sound. Hearing aids tend to work on the ‘half gain’ rule which means that if a sound of 20db were detected at 1000Hz on the left side the hearing aid would provide approx 5db of extra amplification.
Other factors such as the physical properties of the aid would be taken into consideration it is also possible to reduce low frequency background noise and the microphone direction of the aid but basically this is how digital hearing aids work.
Most hearing aids now are able to stream sound directly from a smart phone and can be easily controlled by the user via an app.
If Mr Smith were to go to a noisy restaurant he could adjust the aids via his app to get the sound quality he wants.
High frequency hearing loss untreated leads to social isolation and loss of confidence. A hearing aid won’t be the same as a new ear but it is certainly the next best thing!
Contact us in Congleton 01260 290600, Poynton 01625 877505 or Glossop 01457 852233.
