Leave out the noise, leave out the funk

I’ve only had the MacBook for a day and a half and already you’ll have to pry it from my cold, dead hands. Though most of my settings had been transferred via the Migration Assistant, I took a stroll through System Preferences to double check the existing settings and to play around with some of the features my old iBook didn’t have. For example, I enabled the RSS Visualizer screen saver, which wouldn’t run at all on the G3 iBook and set up my Bluetooth phone to work with the MacBook.

But it was on my trip to the Sound preference pane that I found something unexpected. In the input tab, below the microphone input level, there was a checkbox “Use ambient noise reduction.” I had been playing around with recording recently (for my interview with Cyrus in the Macworld podcast the other week), and had noticed that the background computer noise was pretty loud on my PowerMac G3, even with an external mic. I wasted no time firing up QuickTime Player on my MacBook and recording a pair of samples with and without the ambient noise reduction enabled.

Sure enough, the recording with it enabled cut out a lot of the background hum from the MacBook quite nicely. I tried searching for info about the feature on Apple’s website and got bupkis. Both my iBook and MacBook are running 10.4.6, but they’re slightly different builds (the one with the feature is 8I2025). I’m curious to know if this pops up on anyone else’s computer, and whether it’s a hardware or software feature. It only shows up when I select the internal mic, and not the line in, so I would guess it’s a hardware feature. It also doesn’t appear on my parent’s iMac G5 running 10.4.4.

How about it, readers? Care to help shed some light on the mystery of the ambient noise reduction checkbox? Don’t worry, I’m working on a more concise name.