# LoudnessResult A structure that contains perceptual loudness measurements for a song, including integrated, momentary, short-term, and peak values. ``` struct LoudnessResult ``` ## Overview The `LoudnessResult` delivers perceptual loudness measurements that align with human hearing perception, using the Loudness K-weighted Full Scale (LUFS) standard defined in ITU-R BS.1770. The results contain time-based measurements, including integrated loudness, short-term loudness, momentary loudness, and peak amplitude. When used in `SessionResult`, a single `LoudnessResult` contains all analysis values for the entire song, with `momentary` and `shortTerm` arrays containing the complete set of measurements across the song’s duration. When used in the streaming `loudnessResults` context, the framework delivers multiple results progressively during analysis. Each result’s [`momentary`](/documentation/MusicUnderstanding/LoudnessResult/momentary) and [`shortTerm`](/documentation/MusicUnderstanding/LoudnessResult/shortTerm) arrays contain only one value representing the measurement at that point in time. ## Topics ### Getting loudness results [`let integrated: MusicUnderstandingSession.TimedValue`](/documentation/MusicUnderstanding/LoudnessResult/integrated) The integrated loudness of the song, measured in LUFS over its full duration. [`let momentary: [MusicUnderstandingSession.TimedValue]`](/documentation/MusicUnderstanding/LoudnessResult/momentary) An array of momentary loudness measurements sampled across the song in LUFS. [`let peak: MusicUnderstandingSession.TimedValue`](/documentation/MusicUnderstanding/LoudnessResult/peak) The peak amplitude of the song in decibels (dB). [`let shortTerm: [MusicUnderstandingSession.TimedValue]`](/documentation/MusicUnderstanding/LoudnessResult/shortTerm) An array of short-term loudness measurements sampled across the song in LUFS. ## Relationships ### Conforms To [`Encodable`](/documentation/Swift/Encodable) [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Decodable`](/documentation/Swift/Decodable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)