Intercom For Motorcyclists

On a motorcycle, communi- cation between the rider and the passenger on the rear seat is usually restricted to tapping on arms or gesturing in an effort to draw attention to noteworthy objects or events. The safety helmets and the ambient noise (wind, engine and traffic) make a normal conversation imposs- ible, and many a motorcycle en- thusiast is, therefore, confined to the noise in his own helmet. Even if he shouted at the top of his voice, his passenger would not hear him, although they sit quite close to one another. The intercom proposed here should appeal to all motor- cyclists who recognize the dangers involved in gesturing movements from the passenger while riding at relatively high speed. The unit is also emi- nently suited for instructing novice riders or those practis- ing for work in a mail despatch service. Noise cancelling and automatic mute The circuit diagram in Fig. 1 shows that there are two micro- phones for the driver (channel A) and two for the passenger (cha...