IVR Deconstructed

When pre-recording audio files for IVR applications, IVR developers should take note of the following:

For file formats, we recommend encoding it as a .wav file with these specifications:

- channels: mono
- sample rate: 8 kHz
- encoding: 16-bit linear PCM headerless

As for recording tips, we recommend:

- a quiet echo-free environment
- a high quality microphone
- high-end recording software
- always record at the rate you will be playing at

Regarding microphones, a USB microphones is going to give you the least amount of interference for computer audio recordings as a headset tends to pick up a lot of sound from the person wearing it (both movement and breath). We recommend using a USB microphone that is either shock mounted or at least has a padded base placed on a solid surface. It is also critical that you try to maintain this audio environment for future recordings so that even audio recorded at different times can be used in the same IVR application.

Regarding the recording software, we recommend using Audacity, which is free, open source software that allows you to record and edit your sounds. You can find it here in this link: http://audacity.sourceforge.net/

As for some pre-processing tips, you want to make sure that the audio levels for the recordings come as close to peaking volume as possible without ever reaching the peak. If you do reach hit peak volume, you will want to rerecord the audio, as normalizing will not fix the IVR issue of digital clipping. For post processing, you should normalize all of your audio recordings. You should normalize all audio files to the same threshold percentage and we usually do a 90% threshold. This level prevents the audio from clipping on certain phones and keeps a consistent volume throughout your recordings.

Hope these tips help you IVR developers out there.