DESC9115Assignment 2 DSP Product Application
TeleGate
It is with great pleasure that I introduce to you, the next level in clean signal telecommunication, ‘Telegate’.
Telegate is based upon DSP ingenuity and every day practicality. Ever tried to call a friend on a busy street, or at a packed club or venue, and all you can hear is your friend complaining that he or she can barely hear you? This is because mobile phones lack appropriate filters. While in normal circumstances, your voice is the loudest signal entering the microphone; this is simply because of your proximity to it. As soon as your mobile microphone is exposed to traffic, dense pedestrian traffic, or the extraordinary volume of nightclubs, your voice is all too easily overwhelmed, and the person on the other line is left to loosely translate your interrupted speech. However, Teleaudiocom have developed a piece of software able to filter out the background noise of your surroundings, giving your contact a cleaner signal. This technology can be easily marketed to numerous target groups as noise is noise and comes in so many forms and is a response to so many situations that it is only applicable to “clubbers” but to construction workers, the elderly, business men and women in busy CBD’s, and the list goes on. The effect of this technology however is ultimately realized when both the caller and the receiver have this technology installed on their phones.
Never miss a word with Telegate…
So how does it work? Installed on any smart phone via an ‘app’, and coupled with a small contact sensor placed on the front of your mobile phone, TeleGate monitors incoming microphone signal and filtering out unwanted noise. But how does it know? The contact sensor is placed on the side of the phone that is pressed to the users face. The sensor is able to pick up your voice and, in real time, analyse the volume of your voice as you speak. By doing this, the software is able to distinguish between your voice, and the sounds coming from around you (whether they be soft or loud).
Telegate utilises noise gate technology. A noise gate is simply a way of filtering a signal. By setting parameters based on volume, you are able to let single pass (open gate) or stop sound from reaching the output (closed gate). It might be easier to understand this concept in this analogy. At a security gate for a corporate building, you require a company ID to gain access. As a crowd of people try to access the building, only people holding the ID will be allowed in, everyone else will be refused entry. A mathematical code has been attached to this document to show how a noise gate works.
The diagram below shows speech that has had the Telegate algorithm applied to it.
You can see how the signal is attenuated when Telegate is activated.
The sensor is an ultra-fine super directional microphone. Because sound moves equally in all directions, the sensor is designed to cancel out all noise that isn’t inside the sensors refined polar pattern.
The above diagram displays the focused polar pattern of the sensor. Because of its precision, even sound sources with very high sound pressure levels, will be so heavily attenuated that speech intelligibility will be incredibly improved. Initially this sensor will be fixed to the phone. While the sensor will be slim, there will be a slight discrepancy between the surface of the phone and the sensor; this discrepancy will however not affect usability or comfort of use. Just like any other microphone, the sound vibrations will be converted to electrical impulses, and the results fed to the phone’s primary microphone engine. The signal from the sensor will set the parameters for the filter on the main microphone, this means that the software will filter out anything that’s not in the data from the sensor. In this way, the receiver of the call should only hear the voice of the caller, with only very minimal artifacts of the background noise.
The software is installed via an application or ‘app’ available on all phones that allow apps to be downloaded on to them. This is where the noise gate is initiated. Parameters are based on decibel values. Magnitude and frequency responses are used to give the exact DNA of the spoken voice. It is important to not that the power in this product is it’ ability to analyse the voice in real time, not pre-defined averages. So every time the caller makes a call they can be assured that the software is analysing that exact message. As stated before the data received from the sensor microphone defines the speech parameters of the caller, so anything else witnessed by the phones normal microphone is disregarded as useless information.
We wish to propose this technology to you, the leaders of the mobile manufacturing companies, because we believe that there is a better way to implement this technology. We would like to suggest the manufacture of a phone where the sensor is integrated, further increasing usability, and adding a sense of style and individuality. The suggested phone would also come with the ability to switch the sensor on and off, as normal calls in normal scenarios may be preferable.
In evaluating this product, it is important to consider that many refinements would have to be made before we could confidently say that the filter would cut out everything but the voice, and in many ways this may never be possible, at least in a user-friendly way. While the basis of this technology has been used in many digital signal-processing applications, this application is unique and has an incredibly wide demographic incorporating numerous target markets that could, in our minds, be easily convinced of the benefits of this technology.
It is important to note that the mathematical code included is merely the basis of what would be implemented. And is used purely to demonstrate how a noise gate works. In order to construct the entire working program we require funding from venture capitalists such as you.
We hope that you have seen the potential of Telegate from Teleaudiocom, please join is in the future of mobile phones.