Patent ID: 7873427

Claim:
A computer-implemented method for testing a record gain associated with a computer sound card having a wave table synthesizer and a memory storing a sample of a pre-produced digital tone, the method comprising executing a diagnostic application program on a computer containing the computer sound card, the diagnostic application program, when executed by the computer, configured to: utilize the wave table synthesizer of the computer sound card to play the pre-produced digital tone from the sample stored in the memory of the computer sound card at a first volume intensity and a second volume intensity; convert the pre-produced digital tone at each of the first and second volume intensities to analog format tones; pass the analog format tones to a mixer of the computer sound card; after the analog format tones are received at the mixer, loop the analog format tones through an internal loopback mechanism of the computer sound card to a recording audio channel of the computer sound card; convert the analog format tones to second digital format tones at each of the first and second volume intensities; record the second digital format tones at each of the first and second volume intensities; convert each of the recorded second digital format tones from a time domain to a frequency domain; calculate a first record gain value for the recorded second digital format tone at the first volume intensity; calculate a second record gain value for the recorded second digital format tone at the second volume intensity; and if the first record gain value varies from the second record gain value in proportion to a variation between the first volume intensity and the second volume intensity, designate the recording audio channel as passing a record gain test.