An exhaust note is a term used in automotive and motorcycle enthusiast communities to describe the sound produced by an engine's exhaust system. It refers specifically to the tone, pitch, and volume of the noise emitted from the tailpipe when the vehicle is being driven or idling. The "note" can vary depending on factors such as the type of engine (gasoline, diesel), the size and shape of the pipes, the muffler used, and even the driving conditions. Exhaust notes are often described in terms of their musical qualities - for example, a deep rumble might be referred to as "musical" while a high-pitched squeal could be considered "unpleasant." In some cases, enthusiasts may modify their vehicles' exhaust systems to achieve a specific sound that they find appealing.