Listening Vehicles: The Development of Acoustic Sensors in Vehicles

People want smarter cars. Over the last few years, the global smart car market, including vehicles with artificial intelligence, connectivity, and autonomous driving features, has boomed. In the coming years, experts forecast the smart car market to grow from $57.5 billion in 2022 to $265.7 billion in 2032. That is an impressive compound annual growth rate (CAGR) of 17%.  

The growing interest in smart car ownership is due to the enhanced safety features, comfort, convenience, and ease for drivers and passengers, according to Market.us. The rising adoption rate of electric vehicles (EVs) has contributed to the growing trend of drivers seeking smart vehicle features, also known as “connected vehicles.”

Connectivity within vehicles refers to how smart car features operate with each other. This includes a vehicle’s sensors, cameras, navigation systems, and computing power, enabling it to interact with the external and internal environment and make decisions based on real-time data collected from its technology system. These “decisions” help drivers decrease the risk of traffic accidents through its advanced driver assistant system (ADAS), which reduces human error contributing to possibly fatal accidents.  

The technology that comprises a typical ADAS system includes radar or light, detection and ranging (LIDAR), camera, and ultrasound to gather environmental data. With these cameras and sensors connected over an ADAS, vehicles can offer drivers cross-traffic alerts, parking assistance, blind spot detection, emergency braking, pedestrian detection, collision avoidance, surround view, and lane departure warning, among many other features.  

According to chipmaker Synopsys, vehicles are the “foundation of the next generation of mobile-connected devices, with rapid advances being made in autonomous vehicles.” New solutions are being incorporated into systems on a chip (SoCs), with these chips connecting sensors to actuators through interfaces and high-performance electronic controller units (ECUs). Technological advances, safety efficiency improvements, consumer preferences and demand, and government incentives are a few of the driving factors contributing to these developments.  

One of the latest studies to increase the efficiency of vehicle ADAS is the evolution of acoustic sensors for automotive use.  

Most modern vehicles are insulated against external noise to meet customer preferences concerning driving comfort at high speeds on busy highways. Unfortunately, this comes with an often-overlooked consequence, as noises critical to driving decisions are muted or heard too late. These vital noises are ambulance sirens, wet roads, or even roadway debris. The solution is currently being examined by experts at the Fraunhofer Institute for Digital Media Technology (IDMT) in Oldenburg, who are developing intelligent acoustic sensors for “The Hearing Car.”

Audio Will Improve Advanced Driver Assistance Systems Research Shows

These sensors will utilize an “artificial intelligence-based system for acoustic event recognition in the vicinity of vehicles.” Conventional vehicle sensors have reached their limits for noise detention, so the IDMT’s Hearing, Speech, and Audio Technology (HSA) team will work to equip cars with a better sense of hearing. This system will work with the ADAS found in vehicles to provide better information to drivers.

Moritz Brandes, the Project Manager of the Hearing Car at IDMT in Oldenburg, explained, “On behalf of car manufacturers and suppliers, we are developing and testing new sensor technologies and algorithms for acoustic environment monitoring, source localization, signal enhancement, and speech interaction on both test tracks and roads.”

These acoustic sensors are expected to complement camera systems already utilized in a vehicle’s ADAS. The HSA branch of IDMT is conducting specific research on algorithms that can correctly identify traffic-related noises, based on acoustic detection. These sensors will help further increase a driver’s surrounding perception, assisting them before movements such as lane changes to prevent accidents. Similarly, these sensors can help identify nearby pedestrians when parking, assisting drivers to park without opening their windows.  

Beyond safety assistance, acoustic sensors can help increase vehicle personalization and comfort by adjusting the sound of audio devices drivers and passengers prefer. These systems can be integrated into a vehicle’s infotainment system and serve as the basis for all future audio playback once preferences are set, regardless of the driving situation.  

Inventory for Acoustic Vehicle Sensors Increased Year-on-Year

With personalization and efficient safety features as two of the main driving forces in the global smart car market, acoustic sensors should be on the rise leading to price trends increasing and inventory levels declining.  

According to Sourcengine’s real-time inventory and price data, acoustic sensor inventory levels have been rising instead. Likewise, the average price level for acoustic sensors is declining. This is indicative of a market downturn over the last few months. This downturn could be due to a few factors.  

• New Preferred Vendor: The vendors studied in the data chart have seen inventory levels rise and prices decline, but others may be experiencing different buyer trends. Automotive OEMs, CMs, and EMS providers might be purchasing from the same vendor, which could put acoustic sensors at risk of a future shortage.  
• Recession Concerns: Over 2023, consumer spending has been low due to high energy prices, inflation, and recession concerns. The average selling price (ASP) for vehicles increased over the global semiconductor shortage and has remained high for 2023. Consumers might not have the buying power, leading to a slow component market.  
• Limited Component Inventory: During the global semiconductor shortage, there were not enough chips, and many vehicles sat in lots for months waiting for shipments to arrive. Remaining shortages of some components exist. However, automakers are rapidly trying to meet supply demand and, as a result, cutting features that are optional for a final product. While acoustic sensors see inventory growing, there might not be enough other components to create a functional auditory sensor system.  

There is no one answer to the current data trend, as the global supply chain is usually affected by multiple factors rather than one singular point. For now, acoustic sensors are more available for buyers at a better price than in the past year. Automotive OEMs, CMs, and EMS providers looking to kick off their next auto application project can find their next acoustic solution on Sourcengine’s global marketplace for electronic components.

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