Hearing Aid Channels...Do I need more than 4 Channels in my Hearing Aid?  
Some new hearing aids can come with 24 channels or more… and have a price tag of $2000 to $3000 per aid.  One might assume that more channels or bands will equate to better performance or more benefit. But is that actually true?Starkey, a hear aid manufacturer, did a study involving 1,156 audiograms (study was published in audiologyonline.com). Their goal was to determine how many independent channels were needed to maximize speech audibility - how clear you hear words. Their initial assumption was that a well-designed hearing aid can and should maximize sound quality and speech understanding -  – and this was measured by how sharp or clear words sounded to a hearing aid wearer - which is called the Articulation Index or "AI".  The results of the study may surprise you. Starkey found that the most significant improvement occurred within the first four channels. In other words, the greatest improvements were seen in people moving from one channel to two, two channels to three, or three channels to four. Some improvements were also seen moving from five to six channels, but it was such a small improvement that is was considered to be statistically insignificant. Beyond six channels they were unable to show any improvement in how clear the words word at all.  This image and video below will explain what bands/channels are and how many channels you are actually paying for...
This could be called the 7th secret in the Hearing Aids Secrets.  I have talked to many folks that have talked to their Audiologist..where they recommended a hearing aid with 10 channels,  17 channels or more.   I thought I would do a little research about channels to see if 17 channels was worth the higher prices.   Here is what I found.....
Watch this:
And then read this if you want more technical information, 
The following paragraph is from Audiology Online,  Audiology Online
By Lynda Clark , M.S., CCC-A
Here is my conclusion from reading this,  4-6 channels is optimum.   From what I read here is that you do not need any more than 4-6 channels.  So, save yourself some money.