AudioCapture: Pristine audio for more memorable videos 1/2
Picture this! You just started your summer vacation and arrived at the type of gorgeous beach you only see in the movies with the gentle sound of waves lapping at the shore. You want to capture that moment and, of course, share it with your family and friends. You take out your smartphone, shoot a quick video and share it on Facebook. But when you get home you realize that instead of wave, the only sounds the phone picked up were the wind and the beach bar music that was playing in the background. Poor sound quality has ruined the moment you wanted to keep.
Wind, background noise and other sounds that were not so noticeable when shooting the video have become disruptive elements of the captured audio. Removing these annoyances has proven to be a complex challenge and one that, until now, has not been fully tackled. Now, our LifeVibes AudioCapture software for smartphones compensates for their audio limitations.
Why does the recording sound different?
There are many reasons the recorded audio sounds different from what you remember, but one of the main reasons is that microphones capture sound in a different way than we do. Let’s take a look at a few key examples.
A human ear simply does not perceive wind noise as loudly as an exposed microphone does. Even the slightest breeze can create a roaring and crackling sound on the microphone. Professional outdoor audio equipment solves this by protecting the microphone with a fluffy windshield. On a smartphone, due to aesthetic design and limited space, shielding against wind is often limited. This makes high quality outdoor recording a very challenging task.
b) Phantom noises
Some noises the microphones pick up, are simply not ‘there’, meaning they do not originate from actual sounds. This comes from the fact electronic components and transducers are not perfect. A microphone has a certain self-noise, amplifiers introduce noise and there could be interference from other circuits on the phone.
c) Power to focus
Humans unconsciously focus their hearing on certain sound sources and filter out undesired sources. Smartphones are typically equipped with two (or more) omnidirectional microphones. These microphones pick up sound equally well from any direction. As a result, the sound scene captured by the microphones is much larger than the video scene, which is limited to the camera’s viewing angle.
In addition, some of the cues our brain uses to focus on a particular sound are missing in microphone recordings. This makes it more difficult or tiring to ignore an undesired source.
There are hardware based solutions available. For example: You can buy a separate microphone and connect this to your smartphone. These are cumbersome solutions which can interfere with spontaneous recording of precious moments.
In the next week’s article we will look at how NXP Software’s LifeVibes AudioCapture software solution handles these challenges.