Mobile computer systems, such as laptop or notebook computers, usually include a CD-ROM drive which can be used for music enjoyment. Typically, a user listens to an audio CD through a standard set of headphones while typing or using the computer. Further, audio may be enjoyed by the user from other sources, such as DVD drives and other storage devices, and network connections as well as part of games and other applications which provide an audio component.
Since a notebook computer is mobile, the user is able to operate the computer in a variety of locations while still listening to audio via the headphones. However, many of these locations present a noisy environment to the user. The quality of the audio heard by the user is reduced when mixed with background noise from the local environment. For instance, when a user listens to music while operating the notebook computer on an airplane flight, engine noise is mixed in with the audio provided from the CD, even when using headphones. Office locations also present noisy environments to the user.
Consumer electronic manufacturers have introduced standalone headphones that have a noise reduction system incorporated directly into the headphone. Since a standard headphone set does not contain any processing capability, manufacturers of the noise reduction headphones add a microcontroller or digital signal processor (DSP) to provide a noise canceling signal. Noise reduction systems detect ambient sound surrounding the user and generate a sound wave which is opposite the sensed ambient sound. The opposite sound wave is combined with the ambient sound, resulting in cancellation of the ambient sound.
Because these standalone headphones have noise cancellation capability, they are more costly than a standard headphone set. The addition of a microcontroller or a DSP, and a built-in microphone to collect the ambient noise contribute directly to the increased cost, which in general may be as much as five times more than the standard headphone set.
Therefore, what is needed is a cost effective way to reduce or cancel environmental background noise normally heard by a user through a standard set of headphones while listening to audio while using a mobile computer system. For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art to provide a noise reduction scheme for a mobile computer system without incorporating additional circuitry directly into a standard headphone set.