Some have also called it voice recognition but that term is defined differently. Other names of speech recognition are speech-to-text (STT), computer speech recognition, or automatic speech recognition (ASR). It is a method to change unstructured data (data not organized in a pre-defined manner) into structured data (organized, machine-readable, and searchable). speech-to-text) converts audio data into data formats that data scientists use to get actionable insights for business, industry, and academia. In this article, we’ll talk most about speech recognition APIs, but you will want to use a number of tools to first edit, filter, and improve audio.īut first, let's go over some of the basics. As we move towards a world full of VR and ambient computing, learning how to use these APIs is going to be an important part of new architectures. If you’ve been paying attention to hardware and software trends, you’ll notice speech recognition, audio analysis, and speech creation have become top of mind for modern developers. (the computer song that I wrote was about 1 minute duration and took about two weeks to produce).“Hey, Alexa, is speech recognition really important?” Producing high quality text-to-speech is not easy and can be extremely time consuming. If you have a lot of text-to-speech to produce, it may be more time efficient to edit the voice data (the original recordings that are used for generating the speech) or create your own voice data set. Minor adjustments to the length of a vowel sound can be made by copying a few cycles of the waveform and repeating them. This latter effect is higher quality, but is a bit buggy in the current version - I would recommend installing the Nightly version of Audacity if you uses this effect extensively. In Audacity 1.3.12 you can use the “Stretch Tempo” or “Sliding Time Scale/Pitch shift”.

I’ve only played very briefly with Festival so I’m not familiar with how to manipulate individual phonemes, but I would guess that it is possible. For example, if saying “This is some spoken text”, rather than slowing the whole thing down (t-h-i-s…i-s…s-o-m-e…s-p-o-k-e-n…t-e-x-t), it would primarily be the vowel sounds that would have their durations increased (theeeis eees soeeerm spoThe process was very labour intensive, but I was happy with the final result. To generate slow speech (slow words singing), it was necessary to stretch certain phonemes, but not others. It doesn’t have the best sounding voices, but it provided easy access to the speech generation on a phoneme to phoneme level. The speech engine that I was using was the one from Creative Labs. To produce the best results involved making adjustments within the speech engine before generating, rather than trying to fix things up after generating. For example, I could make the voice “smoother” but it would also become less clear. I tried many methods of post-processing the speech output, but there was little that could make much improvement - filtering, adding reverb, dynamic processing and so on would make some improvement to some aspect of the sound, but at the expense of another. For singing, the pitch and duration of words are obviously of great importance. This was using a text to speech engine, not Festival, but I imagine that many of the same principles apply. Many years ago I produced a performance piece that involved singing computers. That’s also why “smoothness” is so important. That’s why I’m slowing the voice down, and adding pauses. The project needs to generate text-to-speech audio files of algorithmically written bedtime stories. The voice is basically Festival’s “voice_kal_diphone”, but I’ve changed the durations and pauses to slow it down. You need sound samples that start and finish with every other sound sample so that they can be pieced together smoothly with no gaps Most people say good enough and live with it With each letter done in combination with each other letterīut you would have to pick the correct letter in the font to useīased on the starting and ending letter surrounding itīut only way if you dont want those gaps and glitches What you really needed was 26x26x26 sized font Is there a similar process I can do to a wav file?Īnd you want them to look like real handwriting when you printĪnd some of them dont match up with others … I’m wondering if there’s a method for smoothing this kind of thing out?Īn analogy: If you have a photograph with harsh artifacts from a bad digital camera or a bad image compression, you can sometimes correct this by softening the picture in your image editor, then resharpening it.

Audacity speech to text