( 25 ms – 30 ms – 40 ms – 50 ms ) ( / Maximum – / Average )

- Frame Length

● Normalization :

( 25 ms – 30 ms – 40 ms – 50 ms ) ( / Maximum – / Average )

- % Overlap ( 40 % – 50 % – 60 % )

● Framming :

● Silence removal : ( Threshold Based )

● Windowing : ( Hamming window – Hanning window )

Audio Signal Preprocessing

● Filtration : ( LPF – HPF – BPF – BRF ) ( With the same length )

Time

Freq.

● Signals alignment : ( Zero padding - Constant # frames )

Audio Signal Preprocessing

● Silence removal :

X

X

Audio Signal Preprocessing

● Normalization : ( / Maximum )

Audio Signal Preprocessing

- Frame Length ( 30 ms ) - % Overlap ( 60 % )

● Framming :

Audio Signal Preprocessing

● Windowing : ( Hamming window )

Audio Signal Preprocessing

● Signals alignment : ( Zero padding )

0.119 -0.968 -0.076 -0.597 -0.236 2.296 -1.404 0.119 0.954 0.240 0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.119 0.954 -0.236

2.296 -1.404

0.119 -0.968 -0.076 -0.597 -0.236 2.296 -1.404 0.119 0.954 0.240 0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.119 0.954 -0.236

2.296 -1.404

0 0 0 0 0

1 ^st

method

Audio Signal Preprocessing

● Signals alignment : ( Zero padding )

0.119 -0.968 -0.076 -0.597 -0.236 2.296 -1.404 0.119 0.954 0.240 0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.119 0.954 -0.236

2.296 -1.404

0.119 -0.968 -0.076 -0.597 -0.236 2.296 -1.404 0.119 0.954 0.240 0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.679 -0.968

0 -0.076 -0.597

0 -0.236

2.296 0 -1.404

0.119 0 0.954 -0.236

0 2.296 -1.404

2 ^nd

method

Audio Signal Preprocessing

● Signals alignment : ( Constant # frames )

0.119 -0.968 -0.076 -0.597 -0.236 2.296 -1.404 0.119 0.954 0.240 0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.119 0.954 -0.236

2.296 -1.404

30 ms

50 ms

Audio Signal Preprocessing

● Signals alignment : ( Problem of constant frame length )

0.119 -0.968 -0.076 -0.597 -0.236 2.296 -1.404 0.119 0.954 0.240 0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.679 -0.968 -0.076 -0.597 -0.236 2.296 -1.404

0.119 0.954 -0.236

2.296 -1.404

30 ms

30 ms

Audio Signal Preprocessing

● Filtration : ( LPF – HPF – BPF – BRF )

Audio Signal Features extraction

1- Time domain features :

• ^Energy

• Zero Crossing Rate

• Average Magnitude

Time Domain Features

-

2 Frequency domain features :

Short term energy, (Est).

Short term ZCR, (Zst).

Mean frequency, (𝑓𝑚𝑒𝑎𝑛).

Standard Deviation, (𝑓𝑠𝑑).

First Quartile, (Q25).

Third Quartile, (Q75).

Interquartile range, (QIQR).

Skewness, (𝑓𝑠𝑘𝑒𝑤𝑛𝑒𝑠𝑠).

Frequency centroid, (𝑓𝑐𝑒𝑛𝑡𝑟𝑜𝑖𝑑).

Mean fundamental frequency, (𝐹𝑚𝑒𝑎𝑛).

Mel Frequency Cpestral Coefficients, (M𝐹CC11).

1109 954 0.240 0.679 -0.968

0.076 0.597 0.236 2.296 1.404 0.316

Ex:

Frequency Domain Features

Time vs Frequency Domain

Time

Freq.

Speech Energy

)

2 ( m X

m

E n  ^







Speech Energy

Signal ZCR

Signal ZCR

STE vs ZCR

Signal

Energy

ZCR

Average Magnitude