The model also included a microphone which can monitor background noise and determine whether to amplify certain sounds - such as speech - to improve the listening experience.

BBC: shows off 'perceptive radio' that can alter scripts

It easy to forget when you're standing in the middle of a city of birds - but listening to these sounds now, I can't help remembering that the albatrosses and penguins populations are declining sharply for reasons known and unknown.

NPR: Bird Sounds Recorded from Far Afield