A microphone on a sewer camera monitor turns a recording into a report: the operator calls the distance and the finding and both are on the file. When the clip plays back silent, the narration is gone and the report has to be rebuilt from memory. The causes are usually trivial and occasionally a dead microphone, and they are checked in an order that finds the trivial ones first. This guide is that order.
Quick answer: check the audio recording toggle in the monitor’s menu, which many recorders ship switched off and which a gloved thumb can switch off again; check that the microphone opening is not covered by a case flap, a visor or tape; play the file on a different device and in a different player, since some players and some phones drop the audio track from AVI files; check whether the recorder’s format carries audio at all, because a few budget monitors record silent video and some record audio only in one of two modes; and only then suspect the microphone, which is tested by recording a clip while speaking directly at it and listening on headphones.
Check one: the audio toggle
Most monitors with a microphone have an audio on or off setting in the recording menu, and many ship with it off. Some have a dedicated button on the front panel. HBUDS and Sanyipace listings on this site, for example, state that audio recording can be toggled. Find the setting, turn it on, record a test and play it back on the monitor. This is the answer most of the time. Monitors with audio recording covers which reels have the feature.
Check two: the microphone opening
The microphone is a small hole in the monitor housing, and it is covered by a case flap, a sun visor clip, a screen protector that overhangs, tape, or a thumb more often than seems likely. Find the hole in the manual’s diagram and look at it. Clean it gently if it is blocked by grit; do not poke anything into it.
Check three: playback
A file that has audio may play silent on the wrong device. Phones and some computer players handle AVI audio badly or not at all; a converter that was told to drop audio produces silent MP4s; a monitor’s own speaker may be muted or the volume at zero. Play the file in VLC on a computer with headphones before concluding there is no audio in it. File formats and how to open them covers the players.
Check four: the format and mode
A few budget recorders record video without an audio track in any mode, and the listing’s microphone was for a speaker or a voice note feature rather than the video. Some record audio only in a video mode and not in a time-lapse or photo mode. Some record audio to a separate file. The manual says which; the listings on this site record what each listing states about audio. DVR vs card recording covers the recorder types.
Check five: the microphone
With audio on and the opening clear, record a thirty-second clip while speaking at the microphone from a few inches, then play it on a computer with headphones. Nothing at all means a dead microphone or a fault on its circuit, which is a warranty claim if the monitor is young and a maker repair if not. A faint, distorted or crackling voice means a microphone damaged by water or grit, with the same answer. Warranty claims covers the claim.
Wind and handling noise
Audio that is present but useless, all wind roar and reel clatter, is a placement problem rather than a fault. Shield the monitor from wind, speak close to the microphone, and keep the reel’s noise away from it; a monitor on a bracket above a grinding drum records the drum. A piece of open-cell foam over the opening, not blocking it, cuts wind.
Audio out of sync
Narration that lags or leads the picture is a recorder or player problem, usually with AVI files and variable frame rates, and converting to MP4 often fixes playback. It does not affect the report if the distance is spoken.
External microphones
A few monitors accept an external microphone or a headset through a jack, which puts the microphone at the operator’s mouth and away from the reel. Where available it is the best fix for noise. Check the jack is not left with a dead headset plugged in, which mutes the internal microphone on most designs.
If there is no microphone
Many reels have none. The alternatives are a phone recording a voice memo with the time noted, a written log against the counter, or typed notes on reels with a keyboard. Labelling clips covers getting the information into the file names instead.
Preventing the problem
Include an audio check in the pre-job test: record ten seconds while speaking, play it back on the monitor. Keep the microphone opening clear in the case. Write the audio toggle’s location on a card in the case. The ten-minute pre-use test has the slot for it.
Common questions
Why does my sewer camera video have no sound?
Usually the audio recording toggle is off in the menu, or the file is being played on a device that drops AVI audio. Check both before suspecting the microphone.
Does every sewer camera record audio?
No. Many reels have no microphone and some recorders write silent video. The listing or manual says; this site records what each listing states.
How do I test the microphone on a sewer camera monitor?
Turn audio on, record thirty seconds while speaking at the microphone, and play it on a computer with headphones.
Related guides
See sewer cameras with DVR recording, card not working, and exporting footage.