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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16
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3answers
17k views

human speech noise filter

Does anyone know of a filter to attenuate non-speech? I am writing speech recognition software and would like to filter out everything but human speech. This would include background noise, noise ...
12
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1answer
1k views

Determining how similar audio is to human speech

While looking for an answer to this problem, I found this board so decided to cross post this question of mine from Stack Overflow. I am searching for a method of determining the similarity between ...
10
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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 ...
10
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1answer
361 views

Designing a feature vector for discriminating between different sonic waveforms

Consider the 4 following waveform signals: ...
9
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1answer
240 views

How to segment phone call audio into silence/non silence?

My problem is that I don't know the energy of the background noise, so I can't just threshold the energy. The processing is done in real time, and I have about 500msec to decide. Ideally, I'd want ...
8
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2answers
480 views

What does a “vector” in a hidden Markov model mean?

I know that a Hidden Markov Model (HMM) is used in speech recognition and understand it to some degree. However, what I don't know is how input (speech) is "transformed" to a vector which in later ...
8
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3answers
841 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, ...
7
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1answer
716 views

how does this equation correspond to smoothing?

Please help me understand smoothing of data. This is a follow up to my previous question posted here. Especially the top answer by Junuxx where he says a way of smoothing a function $f(x)$ is: $$ f'[...
7
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1answer
3k 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 (...
6
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3answers
296 views

Why does the excitation signal appear, separated, at high quefrencies in the cepstrum?

So, I've just begun a speech and language processing course and have found the explanation of the process of getting the cepstrum of a signal and its properties a little confusing. The following is a ...
5
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1answer
4k views

Distinguish vowels from consonants

Problem of processing speech. Required to determine the phonemes and identify vowels and consonants. Anyone involved in this? Please advise what work on the subject is worth reading?
5
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2answers
238 views

How do the English pronunciations of “tiu” and “tou” differ?

I'm creating an app (I'm a software developer) that for different sounds (interjections from the user) will do different things. For example if the user says: "Tiu", than it will do task A, if it ...
5
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5answers
258 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 ...
5
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1answer
460 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 ...
5
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3answers
9k views

Is there any free software that can recognize and classify sounds?

i am making a smart home automation software and i would like to know if there is any software that can recognize noises such as speech ,playing music,phone ringing etc The exact software i am looking ...
5
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0answers
560 views

Zero-padding of MFCC coefficients

I am trying to implement speech recognition using backpropagation algorithm, and I have been following this paper. I have followed it all the way, except that it tells me to zero-pad the coefficients ...
4
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1answer
3k views

how important is the pre-emphasis stage in MFCC?

I wrote a simple MFCC routine, using all the steps usually suggested in the literature with the exception of the pre-emphasis stage. How important is this stage? Also, some authors suggest that using ...
4
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1answer
3k views

Using HMM for speech recognition

I'm trying to understand how speech recognition works, when using HMM. I know this post is very long, but that's mainly because I'm a complete beginner, and I since I have no idea what is clear and ...
4
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1answer
793 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 ...
4
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2answers
323 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 ...
4
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2answers
587 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 ...
3
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2answers
5k views

Why is each window/frame overlapping?

I am currently reading up on some speech recognition theory. As it speech signals usually are non stationary, but if a speech is seen in a very small time frame can it be deemed stationary, as would ...
3
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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, ...
3
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1answer
89 views

How to do continuous signal processing (i.e without windowing)?

I'm working in speech recognition research, and I wonder if there is a way to analyse sound just like how ears do (i.e. without windowing), so for example to take some feature continuously with an ...
3
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1answer
777 views

If MFCC vectors are speaker independent, then how can we reconstruct unique speech signals from them?

Reconstructing a speech signal from a collection of MFCC vectors seems to work pretty well, but I've heard that one advantage of MFCCs is speaker-independence i.e. they are more-or-less the same ...
3
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2answers
3k views

Using MFCC in spoken words recognition

We're trying to implement a "simple" speech recognition application in MATLAB (isolated words from a very limited dictionary). We've been trying the following methods: Extract MFCC coefficients for ...
3
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1answer
2k views

How to decide the number of cepstral coefficients?

For audio classification we are using cepstral coefficients, but how should I decide the number of coefficients?
3
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3answers
3k views

How to simulation different kinds of Noises in speech signal?

What are the different kinds of noise in speech signal? How can I simulate the same in Matlab for adding to a clean speech signal?
3
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2answers
728 views

Initial state recognition in HMM

I am building a speech recognition system using Hidden Markov Model in python. I referred to this and this question and its answers, which were very helpful. In my approach, I split the continuous ...
3
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2answers
1k views

Vowel detection using MFCC

Does anybody know a simple way to recognize vowels from MFCCs? (not words, just phonemes: a,e,i,o,u). I heard this is a vastly known problem in DSP with several solutions like SVM, GMM and cosine ...
3
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2answers
852 views

Algorithm to detect if a spoken phrase matches a previously spoken phrase

I would like to create a very simple system that allows a user to train (once or multiple times) a spoken phrase (from 1 word to a whole sentence.) Then the (same) user would speak the phrase back, ...
3
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3answers
3k views

Using MFCC to an ANN Speech Recognition System

I'm developing an Artificial Neural Network based Speech Recognition System using MFCCs. Suppose I have 260 input nodes in the ANN, and this number of nodes corresponds to the number of MFCCs that I ...
3
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1answer
1k views

Automatic Gain Control for voice

I am tasked with designing the logic for an automatic gain control. It won't be a traditional AGC in that it has to run on a computer and continuously modifying the volume is not possible in the same ...
3
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0answers
9k views

MFCC calculation

I've got a project and need to calculate MFCCs. I tried to read some tutorials and then make a MATLAB function but I seem to have wrong answers. I'd like to feed MFCCs to one of the classification ...
2
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2answers
146 views

What do cloud-based speech-to-text services upload to the cloud?

Services like Siri and Google Now perform speech recognition (speech-to-text) on mobile phones by doing part of the computation on a server in the cloud. What do they upload to the cloud? Do they ...
2
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2answers
1k views

Difference Between MFCC of speech and speaker recognition

I am doing my project on speaker recognition. One of my friends is doing his project on speech recognition. Both of us need to calculate the MFCC for feature extraction. Is the MFCC going to be the ...
2
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1answer
571 views

Speech Recognition Project - HMM

I am looking for advice on a project I am thinking about completing (for experience etc..) My project is triggering a set of traffic lights (simulation) using Speech recognition. In theory, I want to ...
2
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1answer
30 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 ...
2
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1answer
919 views

Vector Quantization in Hidden Markov Models

In the field of Gesture Recognition and Speech Recognition (using HMM classifiers), do multiple HMM classifiers (one for each class) share common Codebook (i.e common set of symbols) in Vector ...
2
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1answer
123 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 ...
2
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1answer
101 views

voice recognition

during Zimmerman trial, each camp claimed the yell for help recorded belonged to their side. given that Zimmerman is still aside and the recording still exist, could there be some scientific way to ...
2
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1answer
255 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 ...
2
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1answer
757 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 ...
2
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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 ...
2
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1answer
1k views

Detecting phones in a word audio

I am working on speech recognition for Hindi language. My approach is to map speech to text based on phones. For this, first split the speech into the words and then map each word to text by detecting ...
2
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1answer
354 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 ...
2
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0answers
123 views

Summer Projects - Suggestions

I'm looking for some suggestions and wondered if anyone had any ideas. I have just completed a project in Speech Recognition using MFCC, Dynamic Time Warping and Hidden Markov Models etc.. (Some of ...
2
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0answers
248 views

Most efficient algorithm for comparing two paths

I'm working with a Continuous Hidden Markov Model, and using the Viterbi Decoder which finds the best possible path for a given sequence. Here is how my algorithm works: ...
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2answers
536 views

How to Filter Human Speech from an Audio clip?

I'm looking for an open source library to detect Human speech from an audio clip, such as a wav file.
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2answers
296 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, ...