Audio Watermarking Algorithm with a Synchronization Mechanism Based on Spectrum Distribution

Table 2

Attack types.

Item	Attack type	Description
A	Noise corruption	Add Gaussian noise with 35 dB into the audio.
B	Noise corruption	Add Gaussian noise with 20 dB into the audio.
C	MP3 compression	Apply MP3 compression with 128 kbps.
D	MP3 compression	Apply MP3 compression with 64 kbps.
E	Re-quantization	Re-quantize the amplitude with 16-8-16 bit per sample.
F	Resampling	Change the sampling rate with 44.1-22.05-44.1 kHz.
G	Echo addition	Add an echo with a delay of 100 ms.
H	Echo addition	Add an echo with a delay of 50 ms.
I	Low-pass filtering	Applying low-pass filter with 8 kHz.
J	Low-pass filtering	Applying low-pass filter with 4 kHz.
K	Amplitude scaling	Scaling the amplitude by 1.2.
L	Amplitude scaling	Scaling the amplitude by 0.8.
M	TSM	Apply TSM with −5% on the audio.
N	TSM	Apply TSM with +5% on the audio.
O	TSM	Apply TSM with −10% on the audio.
P	TSM	Apply TSM with +10% on the audio.
Q	PSM	Apply PSM with −1% on the audio.
R	PSM	Apply PSM with +1% on the audio.
S	Jittering	Delete one sample every 500 samples in the audio.
T	Jittering	Delete one sample every 1000 samples in the audio.
U	Random cropping	Randomly cut out 100 samples.
V	Random cropping	Randomly cut out 200 samples.