Keep in mind that hearing aids amplify only those frequencies that they are set for, and nearly all have frequency adjustments that are similar to EQ settings on an amp.
The problem that arrises is most males loose high frequency sounds first, therefore their hearing aids are usually set up to amplify high frequency sounds only, such as a woman's voice. My wife says this is probably why I never wear mine.
Most females loose low frequency sounds first, therefore the vast majority of hearing aids sold to women are adjusted to amplify low frequency sounds.
Consequently, those of us whom must depend on heariing aids for conversational usage can encounter problems when performing because of these descrepencies our hearing ability and the subsequent amplification of only certain frequencies. The hearing aid essentially becomes both a plug and a filter, limiting that particular ear to only those sounds that have been lost through either aging or injury. After more than 40 years of marriage I look at it as a blessing in disguise. She can't hear me and I can't hear her!
Cheers,
Gary