Canon EOS 90D Advanced User's Manual page 297

Sounds from Wi-Fi operations may be captured with built-in or external
o
microphones. During sound recording, using the wireless communication
function is not recommended.
When connecting an external microphone or headphones to the camera,
o
make sure the plug is fully inserted.
The camera's built-in microphone will also record the operation sound and
o
mechanical sound of the camera during shooting. Using Directional Stereo
Microphone DM-E1 (sold separately) may reduce such sounds in the movie.
Do not connect anything other than an external microphone to the camera's
o
external microphone IN terminal.
Because noise reduction is not applied to audio played through headphones, it
o
will sound diff erent from the audio recorded with movies.
Do not change the [Sound recording] settings when listening with
o
headphones. This may cause sudden loud output that may hurt your ears.
In Basic Zone modes, the settings available for [Sound recording] are [On]
o
or [Off ]. Set to [On] for automatic adjustment of the recording level.
Audio is also output when the camera is connected to televisions via HDMI,
o
except when [Sound rec.] is set to [Disable].
The sound volume balance between L (left) and R (right) cannot be adjusted.
o
Sound is recorded at a 48 kHz/16-bit sampling rate.
o
Setting the Sound Recording
297