This file is indexed.

/usr/share/help/C/gnome-help/sound-usemic.page is in gnome-user-docs 3.28.1-0ubuntu1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
<page xmlns="http://projectmallard.org/1.0/"
      xmlns:its="http://www.w3.org/2005/11/its"
      type="topic" style="task"
      id="sound-usemic">

  <info>
    <link type="guide" xref="media#sound"/>

    <revision pkgversion="3.7.1" version="0.2" date="2012-11-16" status="outdated"/>
    <revision pkgversion="3.10" date="2013-11-01" status="review"/>
    <revision pkgversion="3.13.92" date="2014-09-22" status="candidate"/>
    <revision pkgversion="3.18" date="2015-09-30" status="final"/>

    <credit type="author">
      <name>Shaun McCance</name>
      <email>shaunm@gnome.org</email>
    </credit>
    <credit type="editor">
      <name>Michael Hill</name>
      <email>mdhillca@gmail.com</email>
    </credit>
    <credit type="editor">
      <name>Ekaterina Gerasimova</name>
      <email>kittykat3756@gmail.com</email>
    </credit>

    <include href="legal.xml" xmlns="http://www.w3.org/2001/XInclude"/>

    <desc>Use an analog or USB microphone and select a default input
    device.</desc>
  </info>

  <title>Use a different microphone</title>

  <p>You can use an external microphone for chatting with friends, speaking
  with colleagues at work, making voice recordings, or using other multimedia
  applications. Even if your computer has a built-in microphone or a webcam
  with a microphone, a separate microphone usually provides better audio
  quality.</p>

  <p>If your microphone has a circular plug, just plug it into the appropriate
  audio socket on your computer. Most computers have two sockets: one for
  microphones and one for speakers. This socket is usually light red in color
  or is accompanied by a picture of a microphone. Microphones plugged
  into the appropriate socket are usually used by default. If not, see the
  instructions below for selecting a default input device.</p>

  <p>If you have a USB microphone, plug it into any USB port on your
  computer. USB microphones act as separate audio devices, and you may
  have to specify which microphone to use by default.</p>

  <steps>
    <title>Select a default audio input device</title>
    <item>
      <p>Open the <gui xref="shell-introduction#activities">Activities</gui> overview and
      start typing <gui>Sound</gui>.</p>
    </item>
    <item>
      <p>Click on <gui>Sound</gui> to open the panel.</p>
    </item>
    <item>
      <p>In the <gui>Input</gui> tab, select the device that you want to use.
      The input level indicator should respond when you speak.</p>
    </item>
  </steps>

  <p>You can adjust the volume and switch the microphone off from this
  panel.</p>

</page>