2. What is Voice Morphing?
Voice morphing is a technology
that allows for the modification of
a person's voice in real-time. It
involves altering the pitch, tone,
and other characteristics of the
voice to create a new sound. This
technology has a wide range of
applications in various industries,
including entertainment, security,
and healthcare.
Text to
speech
Public
speech
systems
Special
effects
To
diminish
ethnical
barriers
3. Speech Signal Processing
Speech signal processing is a key aspect of voice morphing, as it involves the analysis and
manipulation of speech signals to achieve desired effects. This process involves a number of
techniques, including filtering, modulation, and transformation.
Filtering
Filtering is a technique used to modify the frequency characteristics of a speech signal. This can be
done using a variety of filters, such as low-pass, high-pass, and band-pass filters. Filtering can be used
to remove noise from a speech signal or to enhance certain frequencies to achieve a desired effect.
Modulation
Modulation is a technique used to modify the amplitude, frequency, or phase of a speech signal. This
technique is often used to create special effects, such as distortion or vibrato.
Transformation
Transformation is a technique used to modify the spectral characteristics of a speech signal. This can
be done using a variety of transformations, such as Fourier transforms, cepstral analysis, and linear
predictive coding. Transformation can be used to modify the pitch, timbre, or other aspects of a
speech signal.
4. Vocal Tract Modelling
What is Vocal Tract Modeling?
Vocal tract modeling is the
process of creating a
mathematical model of the
human vocal tract, which includes
the mouth, throat, and nasal
cavity. This model is used to
analyze and synthesize speech
sounds.
Why is Vocal Tract Modeling
Important?
Vocal tract modeling is important
because it allows us to better
understand the physical processes
involved in speech production. By
analyzing these processes, we can
develop more accurate speech
synthesis techniques and improve
voice conversion algorithms.
5. Source-Filter Model
The source-filter model is a widely used model in speech
signal processing that describes the generation of speech
sounds. According to this model, speech sounds are
produced by a sound source (vocal cords) and then
modified by the resonances of the vocal tract (filter).
The source-filter model is based on the fact that the vocal
cords vibrate to produce a complex sound wave, which is
then shaped by the resonances of the vocal tract (tongue,
lips, and other articulators) to produce the final speech
sound. The vocal tract acts as a filter, amplifying some
frequencies and attenuating others, and this shaping of
the sound wave is what gives each speech sound its
unique spectral characteristics.
•The source-filter model is useful for analyzing and
synthesizing speech sounds.
•It provides a framework for understanding the
relationship between the vocal cords and the vocal tract
in speech production.
•The model has been used in a variety of applications,
including speech recognition, speech synthesis, and voice
conversion.
6. Excitation Modelling
Excitation Modeling
Techniques
Excitation modeling
refers to the process of
generating an excitation
signal that can be used
to drive a vocal tract
model and synthesize
speech. There are
several techniques used
for excitation modeling,
including pulse models,
noise models, and mixed
models.
Pulse Models
Pulse models generate an
excitation signal by using
a series of pulses at
regular intervals. These
models are particularly
useful for modeling
voiced speech sounds,
such as vowels and
sonorant consonants.
Noise Models
Noise models generate an
excitation signal by using
random noise. These
models are particularly
useful for modeling
unvoiced speech sounds,
such as fricatives and
plosives.
Mixed Models
Mixed models
combine both pulse
and noise models to
generate an
excitation signal that
can be used to model
a wide range of
speech sounds.
8. Voice Conversion Techniques
Neural Voice Conversion (NVC)
NVC is a newer technique for voice conversion
that uses neural networks to learn the
mapping between source and target speakers.
It has been shown to produce more natural-
sounding converted speech than traditional
SPVC techniques.
NVC involves training a neural network on a
large dataset of source-target speaker pairs.
The network learns to map the source features
to the target features, and can then be used to
convert the source speech to the target
speech.
Statistical Parametric Voice Conversion
(SPVC)
SPVC is a widely used technique for voice
conversion, which involves training a
statistical model on a source-target speaker
pair. The model is then used to convert the
source speaker's voice to sound like the
target speaker's voice.
SPVC involves three main steps: feature
extraction, statistical modeling, and
conversion. Feature extraction involves
extracting relevant acoustic features from
the source and target speech signals.
Statistical modeling involves training a
model to learn the mapping between the
source and target features. Conversion
involves applying the learned mapping to
convert the source speech to the target
speech.
9. Applications of Voice Morphing
Entertainment Industry
Voice morphing is widely used
in the entertainment industry
for dubbing, voice acting, and
creating special effects in
movies, TV shows, and video
games.
Security and Forensics
Voice morphing can be used for
security and forensics purposes,
such as voice authentication,
speaker identification, and
voice disguise detection.
10. Conclusion
In conclusion, voice morphing is a fascinating area of research in
computer engineering that has numerous applications in fields such as
entertainment, security, and healthcare. While there are still challenges
and limitations to be addressed, the future of voice morphing looks
promising with ongoing advancements in speech signal processing,
vocal tract modeling, and voice conversion techniques. We hope this
seminar has provided you with valuable insights into the world of voice
morphing and its potential impact on society.
