Most of the time people recognise a photo is being captured when they hear the trademark CLAP-CLAP sound of the moving mirror. The sound (regardless of its source) is even useful for the photographer who then knows the camera really worked when (s)he pressed the shutter release. Many compacts make the sound electronically if the camera is otherwise too quiet to hear.
Mirror-slap is not the only source of sound. The question is, what makes sound in a DSLR camera, for having a list of all sources of sound that a DSLR creates.
Other questions have been asking about specific sounds, for example:
- How can I turn off the loud sound when I take a photograph?
- What is Quiet mode on a DSLR?
- What is the noise when image stabilization is enabled?
- Why do flashes make a whistling sound when recycling?
- Can anything be done to reduce the shutter sound on my SLR?
Curiousity to these noises rose from a question (in Flickr) where a surprised new owner of a Sony SLT A77 asked about the loud sound he hears when taking a photo. The sound soon turned out to be coming from the lens he used, not from his camera. There sure is a lot of things in motion when we take a photograph.