This is an attempt to demystify three types of common hearing aid programming cables. For most hearing aids you must use the standard CS44 cable. For Phonak/Unitron hearing aids use the CA44a cable. For Starkey hearing aids use the Starkey Purple/Straight cable. Some say that the Starkey Purple/Straight Cable can be used for Phonak/Unitron hearing aids, but I have not tried this.
- CS44 Standard Cable
- CS44a (aka Phonak/Unitron) Cable
- Starkey Purple/Straight Cable
Don’t try to use cables other than the above three. In addition to cables you sometimes need a programming adapter/shoe/pill. For custom/CIC hearing aids you may have to use something like these Phonak Custom Cables. But enough about adapters, this is about three cables.
This miniature stuff is so small that special tools are needed to test pinouts. This is the wire from inside a common twisty-tie wrapped around the multi meter probes;
My starting point was this Standard CS44 Cable Pinout. Though I believe this pinout has an error in describing the left image as “Mini-DIN Male (Hi Pro End)”. I believe it should be described as the female connection located on the Hi Pro;
CC44 (or CS44a) cable showing the small end that connects to the hearing aid. Both CS44 and CS44a cables will look exactly the same. The only difference is that pins 3&4 are reversed for some obscure reason.
Note the red dot visual alignment on top.
Note the cutout physical alignment on top of the round plug.
Starkey Purple/Straight Cable showing the small end that connects to the hearing aid.
Note the red dot visual alignment on top.
Note the cutout physical alignment on top of the round plug.
Standard CS44 Cable Pinout:
CS44a Cable (aka Phonak/Unitron Cable) Pinout:
Starkey Purple/Straight Cable Pinout:
