Why can’t the person hear me when using hearing aids with an Android™ phone? 

During a phone call, your voice is picked up by the microphones of the hearing aid 

Using the hearing aids for phone calls, the following is important: 

• The easiest way to ensure calls are routed through your hearing aids is to answer phone calls using the multi-function button of the hearingaidsor by double tapping on the pinna. 
• For outgoing calls, initiate the call normally. Depending on your phone configuration, the call will be routed to the hearing aids automatically. If not, select the Bluetooth® connection as soon as the call is in progress. During a call, you can change the routing of the call from your phone to your hearing aids. From the phone application screen, simply click the Bluetooth® symbol to enable or disable the transmission to your hearing aids.
  Please NOTE: Some phones transfer the call automatically to your hearing aids if the call is picked up by the hearing aid multi-function button, but stays on the phone if the phone’s button is used.
• Check reception on your mobile phone and move to a location with better reception if necessary.
• Check the microphone ports on the hearing aid for debris. If there is debris, use a brush or cloth to clean the microphone ports. If the problem persists, contact your hearing care provider.
• If you are in a very noisy environment, the own voice pickup through the hearing aids may be disturbed too much. In such a case, relocate to a calm environment or alternatively route the call to the phone and directly talk into the phone microphone normally.
• To test whether the call is wirelessly transferred to your hearing aids, speak into your phone. If the other person can hear you better when talking into your phone, route the call to your hearing aids as described above.
• If this does not work, delete the pairing from your phone, reboot the phone and hearing aids, and then re-pair them to your phone.