Recording Audio for CommCare
Audio in CommCare can be used to help both the Mobile Worker and their clients user connect to messages on screen. This can be to guide an interaction for data collection or to provide counseling messages. Below is some guidance for how to record and upload audio files to CommCare!
In order to minimize the time and data needed for installing an application over the network, it is essential to compress the audio to 56-64kbit mono ABR encoding at 22 050Hz, resulting in about 7kB per second or 0.4MB per minute. See the Audacity section below for more details.
File Types
Audio files must be in mp3 format. If your audio files are in another format, use this online tool to convert your files, at 128kbit/s. Then, import into Audacity to complete processing.
Guidelines for Good Recordings
If using Zoom H1 Microphone
Carry extra batteries.
Turn On: Slide power switch down for 1 second
Turn Off: Slide power switch down for 1 second
Reducing Noise: Back of Recorder – Low Cut On will reduce any wind or background noise.
Input Level: Can be automatic by switching Auto level – On (back of recorder). Or can be done manually (recommended settings to come)
Output Level: Volume that will come through your headphones. Manually adjusted near headphone input.
Recording Format: Wave Format is higher quality sound than MP3. Change the Bit Rate using the arrows (this will only change if SD card is inserted). Recommended settings would be 48/16 or 48/24. Higher bit rate results in highly quality audio recordings, however, decreases the recording time of the card. Depending on the length of the audio recording, the bit rate can be adjusted appropriately.
Listening to Recordings: After recording, you can use the play button on the side to listen to any recording. The side arrows will allow you to choose which recording you would like to listen to. As the recording plays, the remaining time of the recording will be shown. The playback can be heard using your headphones or simply through the recorder.
Deleting Recordings: While the playback is running or when it is complete, you can press the trash key to delete. Press the Record button for confirmation of the deletion. A message ‘Done’ should appear once the deletion is complete.
Processing Audio Using Audacity
Processing audio for CommCare involves five easy steps which include: (1) Splicing; (2) Background Noise Removal; (3) Blank Noise Removal; (4) Pauses; and (5) Amplification. Steps 1-3 can be done for each clip individually and steps 4 and 5 can be done in bulk. Please also see our video demonstration on how to use Audacity for processing to help you along the way!
Audio Processing Tutorial English | Audio Processing Tutorial French |
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