How Speakers Auto-Adjust Sound for Any Room

This patent describes a system where a computing device measures a room's sound characteristics, finds a matching sound profile in a database, and then tells a speaker how to adjust its sound for that specific room and speaker type.

What it covers

The patent outlines a method for automatically calibrating a playback device, like a speaker, to its environment. First, a computing device keeps a database of 'representative spectral characteristics,' which are like sound fingerprints for different room types or acoustic conditions. The system then receives 'particular spectral data' from the specific room where the speaker is located. This data describes how sound behaves in that particular space. Based on this measured data, the computing device identifies a matching spectral characteristic from its database. It then uses this identified characteristic, along with details about the specific speaker, to find a suitable 'audio processing algorithm' in the database. Finally, the computing device sends this algorithm to the speaker, telling it how to adjust its sound output. For example, a smart speaker might measure the echoes in a large, empty living room, find a database entry for 'large, echoey room,' and then apply an algorithm to reduce bass boom and clarify vocals.

What it doesn't cover

• —Does not cover manual equalization (EQ) adjustments made by a user without a database lookup.
• —Does not cover systems that generate an audio processing algorithm from scratch without identifying a representative spectral characteristic from a database.
• —Does not cover calibration based solely on non-spectral data, such as microphone placement or listener position, without analyzing the sound's frequency components.
• —Does not cover systems that only measure the room without also considering specific characteristics of the playback device itself when selecting an algorithm.
• —Does not cover real-time, continuous adjustment of sound based on dynamic environmental changes, but rather a one-time calibration based on a match.

The clever bit

The novelty lies in using a database of pre-defined 'representative spectral characteristics' and corresponding 'audio processing algorithms.' Instead of calculating a unique solution every time, the system efficiently matches the measured room data to a known profile and applies an already optimized algorithm, simplifying the calibration process.

Why it matters

This technology simplifies achieving high-quality audio in diverse environments without requiring expert knowledge or manual tuning. It ensures that playback devices, from smart speakers to home theater systems, can deliver consistent sound performance regardless of room acoustics. This automatic adjustment improves the user experience significantly, making sophisticated audio calibration accessible to everyone.

Real-world examples

• 1.Apple HomePod room sensing and sound adjustment
• 2.Sonos Trueplay speaker tuning
• 3.Google Nest Audio sound optimization
• 4.Denon/Marantz Audyssey MultEQ XT room correction systems
• 5.Yamaha YPAO (Yamaha Parametric Acoustic Optimizer) systems
• 6.Most modern smart speaker lock screens