auich —
Intel I/O Controller Hub integrated AC'97 audio device
  driver
auich* at pci? dev ? function ?
audio* at audiobus?
The auich device driver supports the integrated AC'97
  audio controller of the Intel I/O Controller Hub. Supported chipsets include
  the i82801AA (ICH), i82801AB (ICH0), i82801BA (ICH2), i82440MX, i82801CA
  (ICH3), i82801DB (ICH4), i82801EB (ICH5), i82801FB (ICH6), i82801GB/GR (ICH7),
  and Intel 6300ESB. The driver also supports SiS 7012, nForce MCP, nForce2
  MCP-T, nForce3 MCP-T, nForce3 250 MCP-T, nForce4, and AMD 8111.
The driver provides the following
    sysctl(8) read/write variable
    (when hardware support is available):
  - hw.auich0.ac97rate
- Link rate of the device in Hz. The driver automatically measures and
      calculates the correct rate so you usually don't need to change this.
      There is, however, a chance that the driver miscalculates the rate
      especially on an emulated hardware, resulting in an incorrect playback
      pitch. When this happens you need to manually set this variable to the
      correct value. Try 48000if you don't know the
      correct value as it is the default link rate.
Theauich device driver appeared in
  NetBSD 1.6.
The ‘microphone’ input DMA channel is not currently supported.