Public address system and method for an urban transit vehicle

#The present invention generally relates to public address systems. More particularly, the invention is directed to apparatuses and methods for providing a noiseless public address announcement in a transit vehicle without compromising the safety of the vehicle or the passengers within.

#The duties of a bus driver, and other operators of modern urban transit vehicles, have grown increasingly complex. Maneuvering an oversized vehicle through mazes of streets and highways in dense traffic requires constant attention by the driver. While technology has well provided buses with a number of tools useful in maintaining the safety and comfort of the vehicle's occupants, these adaptations can themselves become distractions for an already overburdened driver. In the interest of safety, it is important to keep the driver focused on the road ahead.

#People riding on a bus often require information as they ride. One important piece of information that passengers need to know on a timely basis is the name of the next place that the bus will stop, so that passengers who intend to disembark can prepare themselves. In most cases, the bus driver is the only person available to announce that type of information. Because the information must be announced while the bus is actually en route, a time when the driver is busy actually navigating the streets, the driver making the announcement needs to be able to do so with a minimum amount of distractions.

#Other objects, advantages, features and characteristics of the present invention, as well as methods, operation and functions of related elements of structure, and the combination of parts and economies of manufacture, will become apparent upon consideration of the following description and claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures, and wherein:

#FIG. 1 is a simplified schematic of a public address system according to a preferred embodiment of the present invention.

#FIG. 2 illustrates an implementation of a public address system within a transportation vehicle according to a preferred embodiment of the present invention.

#In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

#The conceptual groundwork for the present invention involves providing a public address system that can be operated hands-free while providing clear, noiseless announcements to passengers that are both internal and external to a transit vehicle. The hands-free public address system of the instant invention receives an audible signal via a microphone and processes the signal to reduce undesirable noise. Noise reduction begins through utilizing a directional microphone having a narrow pick-up pattern and noise canceling characteristics. Undesirable noise is further reduced through digitizing the received audio signal and processing the signal using a digital signal processor (DSP). The DSP removes undesirable noise contained within the signal and not associated with the announcement to be communicated. For instance, the DSP uses an algorithm for removing engine noise, A/C noise, and general road noise not associated with the intended announcement. The noise-free signal can then be stored within a memory device and, when needed, the announcement can be retrieved and transferred to an output device such as a speaker.

#Referring to FIG. 1, a simplified schematic of a public address system according to a preferred embodiment of the present invention is shown. System 100 includes noise-canceling microphone 102 for receiving an audio signal or announcement from a vehicle operator. Microphone 102 is controlled by actuator 101 and switch 109 located near the foot of the operator and controlled by the operator foot depressing switch 109. In other embodiments, microphone 102 can be controlled by paddle switches located on the steering wheel or by using a voice activated microphone that turns on when the user commands the microphone to turn on. All in all, the present invention is directed toward operating a microphone within a transit vehicle without the operator having to remove their hands from the steering wheel of the vehicle. Upon actuating hands-free microphone 102, the audio signal is received by microphone 102 and amplified using low-noise amplifier 104. The amplified signal is then fed to digitizer 105 where the signal is converted into a digital signal. Preferably, digitizer 105 has a high sample rate for providing excellent data integrity representative of the information originating from the audio signal detected by microphone 102.