Vehicle horn horn. Bicycles often have a classic "bulb horn", operated by squeezing a rubber bulb attached to a metal horn. Squeezing the bulb forces air through a steel reed located in the throat of the horn, making it vibrate, producing a single note. The flaring horn matches the acoustic impedance of the reed to the open air, radiating the sound waves efficiently, making the sound louder. Other types of horns used on bicycles include battery-operated horns (sometimes even car horns on 12-volt circuits are incorporated) and small air horns powered by a small can of compressed gas. Oliver Lucas of Birmingham,
A&B Sound and management at both branches were greeted to a locked front door and a message stating that the location had been shut down, with no prior notice. Over the next few months, the remainder of the A&B Sound chain collapsed, with its remaining branches closing on the following dates: The collapse of A&B Sound was predicted by retail analysts during the summer of 2008. Retail Analyst David Ian Gray was quoted as saying, "I think they're done. They had to close stores, for sure, but they're getting to a point where their brand is lost, and I just don't see