352kbps 4-bit Mono 22kHz Microsoft ADPCM Possible?

Hi,

My audio source files have these property values…
Bit Rate: 352kbps
Audio sample size: 4 bit
Channels: 1 (mono)
Audio sample rate: 22 KHz
Audio format: Microsoft ADPCM

It is important the edited files maintain each of these same property values. Is this configuration possible with Audacity?

Audacity’s “Uncompressed Export Format” has “WAV (Microsoft 4 bit MS ADPCM)” which matches all the above values except the bit rate is only 89kbps. Is there a way to get the bit rate to match the rest?

Thanks for any help achieving this! :slight_smile:

Something is wrong, but I have no idea where.

The Bit Rate is determined by the Sample Rate * Bit Depth * number of channels. A 4-bit mono file sampled 22050 times/sec will turn out to be 88.2KB/s (aka 89KB/s). I don’t know how you can have a file with those numbers.

Do the ADPCM files that Audacity spits out work? What are you trying to do with them?

Hi,

Thanks for responding. When I searched the web trying to find a way to duplicate these exact values, I stumbled across some comments that such value configurations were found in some older audio files. The original audio files are about 10 years old.

The problem with Audacity is that when exporting, Audacity would introduce spots of static in some files. So I thought a greater bit rate would fix that. Also, I did not want any possible playback issues for users from using two different bit rates.

I haven’t found a way to replicate the 352kbps, but saving the audio files at a higher quality out of Audacity and using another program to convert them to Microsoft ADPCM seems to eliminate the static.