Table of Contents

## How are MFCC features extracted?

The MFCC feature extraction technique basically includes windowing the signal, applying the DFT, taking the log of the magnitude, and then warping the frequencies on a Mel scale, followed by applying the inverse DCT. The detailed description of various steps involved in the MFCC feature extraction is explained below.

**What is the output of MFCC feature extraction?**

The output after applying MFCC is a matrix having feature vectors extracted from all the frames. In this output matrix the rows represent the corresponding frame numbers and columns represent corresponding feature vector coefficients [1-4]. Finally this output matrix is used for classification process.

**What is PLP feature extraction?**

Perceptual linear prediction (PLP) technique combines the critical bands, intensity-to-loudness compression and equal loudness pre-emphasis in the extraction of relevant information from speech.

### What is MFCC feature vector?

The mfcc function returns mel frequnecy cepstral coefficients (MFCC) over time. That is, it separates the audio into short windows and calculates the MFCC (aka feature vectors) for each window.

**How many MFCC coefficients are there?**

Traditional MFCC systems use only 8–13 cepstral coefficients. The zeroth coefficient is often excluded since it represents the average log-energy of the input signal, which only carries little speaker-specific information.

**What is MFCC in speech recognition?**

It is observed that extracting features from the audio signal and using it as input to the base model will produce much better performance than directly considering raw audio signal as input. MFCC is the widely used technique for extracting the features from the audio signal.

#### What is MFCC in simple words?

Mel-frequency cepstral coefficients (MFCCs) are coefficients that collectively make up an MFC. They are derived from a type of cepstral representation of the audio clip (a nonlinear “spectrum-of-a-spectrum”).

**Why are MFCC features used?**

**What is the difference between Mel spectrogram and MFCC?**

Mel-Spectrogram is computed by applying a Fourier transform to analyze the frequency content of a signal and to convert it to the mel-scale, while MFCCs are calculated with a discrete cosine transform (DCT) into a melfrequency spectrogram.

## How do I get MFCC from Mel spectrogram?

To get MFCC, compute the DCT on the mel-spectrogram. The mel-spectrogram is often log-scaled before. MFCC is a very compressible representation, often using just 20 or 13 coefficients instead of 32-64 bands in Mel spectrogram.

**What is the difference between spectrogram and Mel spectrogram?**

The linear audio spectrogram is ideally suited for applications where all frequencies have equal importance, while mel spectrograms are better suited for applications that need to model human hearing perception. Mel spectrogram data is also suited for use in audio classification applications.

**What are the best techniques for feature extraction?**

not present Wavelet Better time resolution than Fourier Tran Dynamic feature extractions LPC MFCCs Acceleration and delta coefficients i.e. Spectral subtraction Robust Feature extraction method Cepstral mean subtraction Robust Feature extraction RASTA filtering For Noisy speech

### What is feature extraction in machine learning?

Feature extraction plays a very important in the recognition process. This is basically a process of dimension reduction or feature reduction as this process eliminates the irrelevant data present in the given input while maintaining important information.

**Is there a feasible method for hand gesture recognition using MFCC?**

CONCLUSIONAND FUTUREWORK This paper has represented a feasible method for hand gesture recognition using MFCC. In this work the given input are converted from 2D Images to 1D signal to be given as input to Mel frequency ceptral coefficients.