What is SAD? SAD is user level sound for user interface. When the computer and human machine interaction via sound pressure happens, you can achieve interactions between humans and machines. The typical goal is fear, and we find that LOUD sound effects very SUDDenly are great for SCARing people  fk what was that.

The goal of this interaction between the operator and the decision making process involved is a broad concept that involves code, the internet, and many other things you noobs would have no idea. Whether its sound for heavy machinery or the ergonomics and psychology required for efficient and enjoyable user friendly interface sounds to produce a calming effect for the operator, Generally speaking, the humans control aspect is left up to the user, which means the operator is required to provide minimal input to the computer to achieve the quickest result and the desired sound output is achieved. This minimizes the interaction with the machine to created personalized results quickly, with amplitude and loudness control, as well as frequency based filtering and EQ in an easy to use interface.

Sound is one of two or possibly 3 ways machines communicate with humans. The user is provided with sounds and effects to enhance the user experience and provide feedback. An example would be that bubble popping noise or beeping as the volume is adjusted to let the user know the approximate volume level.

The corresponding disciplines being acoustics and engineering, most loud sound effects have a lot of the 1.5k-6k region which are very painful and piercing to the human ear. The Psychology of loud sounds and dissonent noises have been used to torture prisoners. I have heard that tank commanders played “Let the Bodies hit the floor on the tank public address systems during tank assaults in Iraq.

When a machine network, equipment, or computers interact with humans via sound, the system may be exposed to many types of users, including users who cannot hear, or varying degrees of hearing ability, so sound should not be essential for the operation, more more likely an enhancement to the experience. The system for user interface may be optimized for user through logging, or through computerized data-bases which provide the user with two options and measures the interaction of the users within the two different interfaces. Bounce rate, or the amount of users that “bounce out” or rage quit is a common metric, as well as user interaction time lengths.  HCI or Human Computer Interaction is and industrial or mechanical means, which is a modification of the term Man Machine Interaction which is considered antiquated and unused due to the gender bias of the term . Without a clean and useable interface, humans will struggle to learn how to use the machine, and varying complexities are common.