Compression method for hearing aids

A compression method for a hearing aid for use by a hearing-impaired person, comprising:

• providing the hearing aid, wherein the hearing aid comprises n frequency channels [C1, C2, . . . , Cn], each of the frequency channels being characterized by a linear gain [GC1, GC2, . . . , GCn)] and lower compression thresholds [(TH1low, TH2low, . . . , THnlow];
• determining compression parameters of each of the n frequency channels [C1, C2, . . . , Cn], the compression parameters comprising compression ratios (CR1, CR2, . . . , CRn), upper compression thresholds [(TH1up, TH2up, . . . , THnup], and gains [GupC1, GupC2, . . . , GupCn] corresponding to the upper compression thresholds [(TH1up, TH2up, . . . , THnup];
• and
• for each channel Cn, setting the upper compression threshold THnup of the hearing aid to an annoyance threshold Fn for the hearing-impaired person based at least in part on:
• THnup=Fn+αn, where αn is a parameter for converting Fn from dB HL to dB SPL,
• wherein, for each channel Cn, the gain GupCn at the upper compression threshold THnup is based at least in part on:
• GupCnTHnup=0 dB;
• and
• wherein, for each channel Cn, the compression ratio CRn is based at least in part on:
• CRn
• =
• 1
• 1
• -
• GCn
• THnlow
• -
• F
• ⁢
• n
• -
• α
• ⁢
• n
• .

A system for implementing a compression method in a hearing aid for a hearing-impaired person, the system comprising:

• a hearing aid comprising n frequency channels [C1, C2, . . . , Cn], each frequency channel being characterized by a linear gain [GC1, GC2, . . . , GCn] and lower compression thresholds [(TH1low, TH2low, . . . , THnlow];
• and
• a processor configured to:
• determine compression parameters for each of the n frequency channels, the compression parameters comprising compression ratios (CR1, CR2, . . . , CRn), upper compression thresholds [(THlup, TH2up, . . . , THnup], and gains [GupC1, GupC2, . . . , GupCn] corresponding to the upper compression thresholds;
• for each channel Cn, set the upper compression threshold THnup to an annoyance threshold Fn for the hearing-impaired person based at least in part on:
• THnup=Fn+αn, where αn is a parameter for converting Fn from dB HL to dB SPL;
• for each channel Cn, set the gain GupCn at the upper compression threshold THnup based at least in part on:
• GupCnTHnup=0 dB;
• and
• for each channel Cn, determine the compression ratio CRn based at least in part on:
• CRn=1/(1−GCn/(THnlow−Fn−αn)).

A fitting method for hearing aids, comprising:

• determining an annoyance threshold Fn for a hearing-impaired person;
• setting an upper compression threshold THnup of a hearing aid for each of n frequency channels of the hearing aid based at least in part on the annoyance threshold Fn;
• setting a gain GupCn at the upper compression threshold THnup for each frequency channel of the hearing aid;
• determining a compression ratio CRn for each frequency channel based at least in part on the upper compression threshold THnup and a lower compression threshold THnlow;
• and
• programming the hearing aid with the determined upper compression thresholds, gains, and compression ratios for each frequency channel.