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Questions tagged [speech-recognition]

Speech recognition is the process of converting the spoken word to text, usually without regard to a particular speaker (which is more commonly referred to as "voice recognition").

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1answer
216 views

MFCC in Speech Recognition and ANN

I have a dataset with over 2000 examples of digits (0 to 9) recorded on wav files. I'm trying to process these files with MFCC so that later I could train an Artificial Neural Network (ANN). My ...
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0answers
12 views

Stack features in wakeword model

I'm not clear how is the input features are stacked in wakeword applications. Taking https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43969.pdf as an example, the author ...
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1answer
67 views

Preprocess sound for voice recognition in Pocket Sphinx on Raspberry Pi 3

I want to improve my voice recognition system on a Raspberry Pi 3 running Pocket Spinx. It's pretty accurate (limited recognition vocabulary) but is terrible when other noise is around. Is there any ...
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12 views

How to use DTW for keyword spotting in human speech?

I am trying to use Dynamic Time Wrapping (DTW) + KNN to detect word occurrences in human speech audio. I am to implement the same approach suggested in this DSP StackExchange post, but I am seeing ...
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2answers
335 views

Matching LPC frequency response to raw sample data frequency response

Background: The intention is feature/formant extraction from speech input. I have used an FFT on raw samples in the past and have done simple peak picking from a weighted average of frequencies over ...
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4answers
86 views

Cleaning telephone audio

I have telephone audio at 16kHz and I am trying to use it with a speech transcription engine that converts spoken letters to text. However, the engine has some difficulty transcribing certain letters ...
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2answers
686 views

Using k Nearest Neighbour & Dynamic Time Warping for keyword spotting

As stated in the title, I am currently researching a method using k-NN, specifically, as either an alternative or as a supplement to the DTW algorithm in keyword spotting based on MFCC. I have read ...
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1answer
599 views

Comparing band-pass filters and convolutional kernels?

I am currently working on extracting features for speech recognition purposes. I wanted to try an approach similar to MFCC features in which the center frequency of each band pass filters are placed ...
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2answers
623 views

Dynamic Time Warping - Comparing Values

Ok, so I'm trying to compare two different speech signals and I have come into a problem. Here goes: I have split the signal into blocks, and I have computed the MFCC coefficients of each block. I ...
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1answer
383 views

MFCC Classification

I'm working on gender estimation from speech signal and I completed MFCC feature extraction. So now I'm trying to estimate gender from these features. But I have frames for an audio file and I ...
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1answer
130 views

How to build a simple model for voice-controlled system?

I want to build a speaker independent voice-controlled system. If I ask 10 people to say one unique word(for example"hello"), and record their voice and do LPC(linear predicting coding) upon them, I ...
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1answer
74 views

Audio from multiple microphones mixed to mono and ASR

I am trying to do speech recognition on an audio file which has 1 channel (mono). My problem is that the channel is comprised of the signal of 3 microphones which have captured the audio at different ...
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1answer
68 views

Why is the Hamming and Hanning window the most widely used for speech spectograms?

When taking the Short-Time Fourier Transform of the speech signal, windowing is applied to taper away the signal frame at both ends and mitigate introduced artifact at expense of the maximum ...
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1answer
36 views

Calculate the Standard Deviation of Fundamental Frequency (MFCC)

I'm implementing a gunshot detector following the article "Algorithm for Gunshot Detection Using Mel-Frequency Cepstrum Coefficients (MFCC)" (paywall). In the article, the authors uses 22 features ...
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1answer
4k views

What's the correct graphical interpretation of a series of MFCC vectors?

I'm studying speech-recognition, in particular the use of MFCC for feature extraction. All examples I've found online tend to graph a series of MFCC extracted from a particular utterance as follows (...
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1answer
88 views

What are i-vectors and x-vectors in the context of Speech Recognition?

I have read that i-vectors and x-vectors are widely used in speaker recognition tasks but I don't get the difference between them and how exactly they work. Can someone explain it starting from the ...
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1answer
20 views

Are delta and double delta features needed when classifying with LSTM

I understand that the combination of MFCCs, deltas and double deltas is a good feature to be used with HMMs for keyword detection problems. HMMs are limited by Markov Property and this limitation is ...
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2answers
315 views

How to edit audios so that they have the same length

I have a dataset of audio files, which differ on their lengths by a couple of milliseconds. Some are little shorter than 1s and some are little longer than 1s. They all have the same sampling rate, ...
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1answer
127 views

Mel separated filter banks

I am currently a bit confused. I am currently trying to understand the MFCC extraction process, and don't understand how the Mel filter banks only provide a scalar output from each filter bank. What ...
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1answer
59 views

Fast Vocal Tract Length Normalization(VTLN) implementation?

My team is building a speech recognition model. As far as I know, Vocal Tract Length Normalization (VTLN) is an effective warping method that may help improve the model performance by diminishing ...
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1answer
39 views

Is there any way that we can perform speech recognition without using Fourier transforms?

I am trying to research about speech recognition and why everyone uses Fourier transforms in going about the topic. I know that we get information related to the frequency of each sound uttered which ...
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1answer
97 views

Split audio file into audio phrases

I have couple of audio recordings of length 5 -7 min. I also have corresponding text to each audio file. I am not subject matter expert on speech to text but I am vaguely aware that much smaller ...
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3answers
1k views

VAD speech databases

Does anybody know any open voice/speech annotated database for Voice Activity Detection? Or any other corpus for speech evaluation purposes? The ones I know are private: AURORA, TIMIT, SpeechDat-Car, ...
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0answers
44 views

What would be the input data matrix and target data matrix in MATLAB Neural Network Pattern Recognition toolbox?

I am new to Neural Networks and have no prior experience of AI,ML or deep learning. Please help me out. I have data sets of 10 different kind of hand-motions(Gestures) from M1 to M10. Each hand-motion ...
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1answer
28 views

Services for phoneme recognition? [closed]

I wonder if anyone can point me to services or dev libraries that focus on or suit phoneme recognition? Target audience is children at learning to read stage. We have trialed IBM Watson (not good) ...
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3answers
888 views

How does Siri recognize me saying “Hey Siri”?

I am trying to understand how my iPhone can continually listening for me saying Hey Siri, Alexa, ...
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2answers
98 views

why the MFCC is gender indenpend and used for isolated word recognition

I think female and male have total different MFCC feature for same word such as "one", but why the MFCC could be used for isolated word recognition which use the same HMM model for the same word ...
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1answer
791 views

Training a CNN-HMM model

I am currently trying to train a CNN-HMM acoustic model for speech recognition. The CNN model is able to detect a center monophone given a context window of x (limits has not been tested yet - but ...
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1answer
160 views

What Is the Point of Doing the Zero Padding? [duplicate]

What are the advantages and disadvantages of doing Zero-padding, in particular the case of speech signals?
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1answer
259 views

RNN as posterior probability estimation in speech recognition with HTK

I'm new to speech recognition and deep learning and in a learning phase. I'm trying to follow this paper to learn how to use RNN as posterior probability estimation in an HTK environment. The paper ...
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1answer
693 views

MFCC window size at different sampling rates

The general recommendation for window size when calculating MFCC seems to be 20-40 msec. This is most often recommended in a context of 16000 samples per second, so leading to a window containing 320-...
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0answers
19 views

Finding fundamental particles of sound In ASR systems? [closed]

Q1. Can we divide phonemes which are specific to a language into some more fundamental entities same across all languages ? Q2. Will this help us in achieving language independent acoustic modelling ...
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1answer
84 views

Signals - Removing Blocks

I'm after some advice on a problem that I am facing regarding signal processing. I am processing a voice clip (.wav) and this voice clip contains noise, and I need to remove the noise and just ...
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1answer
856 views

Speech recognition: words vs. phonemes

One could train a speech recognizer with words or phonemes. I guess that they both have their pros and cons: with words there would be a lower error rate as phonemes can be put together building a ...
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1answer
440 views

Slow implementation DTW for word recognition

I wrote little program for isolated word recognition using DTW algorithm. In folder with main program i have another folder "Data20dict", with 20 more folders in it, and each one is called by voice ...
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1answer
291 views

Interpreting dataset of a power spectrum

I am currently working with kaldi, and are trying to make spectrogram plots of different audio files. Kaldi is a speech recognition toolkit. Kaldi frames its input in frames of 25 ms with a ...
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1answer
80 views

Is there a known correlation between human voice (360Hz to 5kHz) and the frequencies above/below that?

Hello SignalProcessing! Given the important frequencies of a human voice (360Hz to 5kHz) to communicate and the frequencies above and below that make the voice sound way better. Imagine we are ...
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5answers
271 views

Remove a known wav file from recorded file

I looked at many similar questions but still cannot find an answer to my problem. I'm playing an audio file N, while recording a man talking (b). The problem is that the microphone gets the played ...
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1answer
470 views

Does speaker recognition system need the same sample rate audio?

I'm a new man in speaker recognition project. I've train a model with some .wav files, its sample rate is 16000. I want to test this model with my record, but my record's sample rate is 8000 Doed it ...
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0answers
34 views

Is it possible to detect that sound source is playback of a recording?

I have been trying to find an article where it is described how real-time (or close to real-time) signal processing from a microphone is able to detect that an audio source is playback of a recording ...
5
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1answer
463 views

Hidden Markov Model for Speech Rcognition. HMM Number of States

This is a question that came to mind as a result of a previous question Hidden Markov Models - Distinct Observation Symbols and subsequent answer from @pichenettes. One approach to speech recognition ...
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1answer
77 views

Obtaining databases for speech emotion recognition analysis

For a research work on speech emotion recognition, I need the database of CASIA and EESDB for simulations. I could not find those; how can I get them? Thanks.
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1answer
706 views

cceps (complex cepstrum) function in Matlab

My doubt is in regards to the usage of the function cceps in Matlab. The function is giving me the cepstrum for the entire speech signal of 3 or 4sec. This works ...
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3answers
1k views

Speech corpora for VAD

I'm doing a student research project connected with VAD. And I want to find speech corpora with added noise. I found many references to the NIST Speaker Recognition Corpora. But unfortunately, all ...
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1answer
160 views

Keyword spotting - constant phoneme length

I wish to implement a keyword spotting algorithm (in speech), on the basis of what was published in this article (Apple's Machine Learning Journal). The article describes a neural-network-based ...
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1answer
1k views

Why is LPCC and LPC used in speech recognition

I am currently trying to understand why LPCC and LPC is being used in speech recognition and why? LPC as I understand is model similar to source filter model, modelling speech production, and LPC ...
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1answer
128 views

Cepstrum calculus disambiguation

Learning the cepstrum analysis for speech recognition, I have met two different definitions of cepstrum (for discrete signals): $F^{-1}(ln|F(x[n])|)$ . That is, the cepstrum is the inverse Fourier ...
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1answer
90 views

Speech recognition question

I am searching for a software that will translate speech to text but if it does not recognise a word, it will simply write a close resemblance to a word only misspelled, for example, if I say the word ...
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0answers
425 views

The essential pre-processing steps in speech signal analysis

My question is that for simulating a new scheme for speech emotion recognition (feature extraction and classification), what are the necessary pre-processing steps (I mean any kind of normalization ...
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1answer
1k views

How does noise reduction for speech recognition differ from noise reduction that is supposed to make speech more “intelligible” for humans?

this is a question that has interested me for some time now, mainly because I'm working on noise reduction for an existing speech recognition system myself. Most papers on noise reduction techniques ...