- --:--:--:--- / --:--:--:---
Noise Morphing for Audio Time Stretching
Eloi Moliner, Leonardo Fierro, Alec Wright, Matti Hämäläinen, and Vesa Välimäki
Companion page for a journal article submitted to IEEE Signal Processing Letters
The article can be accessed here.
Abstract
This letter introduces an innovative method to enhance the quality of audio time stretching by precisely decomposing a sound into sines, transients, and noise and by improving the processing of the latter component. While there are established methods for time-stretching sines and transients with high quality, the manipulation of noise or residual components has lacked robust solutions in prior research. The proposed method combines sound decomposition with previous techniques for audio spectral resynthesis. %of noisy signals. The time-stretched noise component is achieved by morphing its time-interpolated spectral magnitude with a white-noise excitation signal. This method stands out for its simplicity, efficiency, and audio quality. The results of a subjective experiment affirm the superiority of this approach over current state-of-the-art methods across all evaluated stretch factors. The proposed technique notably excels in extreme stretching scenarios, signifying a substantial elevation in performance. The proposed method holds promise for a wide range of applications in slow-motion media content, such as music or sports video production.
Audio examples: \alpha = 2
Listening test examples
Car: Live recording of a rally car passing by
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Soda: Hiss and click sounds from a can opening
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Cut: A knife cutting food on a cutting board
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
EDM: Electronic music example
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
PP (Ping Pong): Sounds from an amateur ping pong game
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
Additional examples
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Drums
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (EL)
- --:--:--:--- / --:--:--:---
Guitar
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Hand Saw
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Seagulls
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
Audio examples: \alpha = 4
Listening test examples
- --:--:--:--- / --:--:--:---
Car: Live recording of a rally car passing by
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Soda: Hiss and click sounds from a can opening
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Cut: A knife cutting food on a cutting board
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
EDM: Electronic music example
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
PP (Ping Pong): Sounds from an amateur ping pong game
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
Additional examples
- --:--:--:--- / --:--:--:---
Drums
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (EL)
- --:--:--:--- / --:--:--:---
Guitar
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Hand Saw
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Seagulls
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
Audio examples: \alpha = 8
Listening test examples
- --:--:--:--- / --:--:--:---
Car: Live recording of a rally car passing by
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Soda: Hiss and click sounds from a can opening
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Cut: A knife cutting food on a cutting board
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
EDM: Electronic music example
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
PP (Ping Pong): Sounds from an amateur ping pong game
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
Additional examples
- --:--:--:--- / --:--:--:---
Drums
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Guitar
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Hand Saw
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
- --:--:--:--- / --:--:--:---
Seagulls
- Original (Reference)
- Anchor: Phase Vocoder (AN)
- Fuzzy Phase Vocoder (FZ)
- Neural synthesizer (WN)
- Fuzzy Phase Vocoder with Transient Preservation (FT)
- Proposed method without prior decomposition (ND)
- Proposed method with spectral magnitude replacement (NI)
- Proposed Noise Morphing method (NM)
- Elastique (excluded from the listening test)
Supplemental listening test results
Non-parametric test results
