Meet Siri’s Great-Grandfather, the Voder

Voder demonstration
The Voder being demonstrated at the 1939 New York World’s Fair. From the Bell Telephone Magazine, no known copyright restrictions.

Mrs Helen Harper, of Jamaica, New York, had an unusual ability — she could play the human voice with her fingers.

It was 1939, and the world’s first electronic speech synthesiser had just been invented at Bell Laboratories in New Jersey.  The Voder, as it was named, Read the rest

WaveNet: Micro-Managing the Way to Realistic Synthesised Speech

Net with cool lighting
Photo by Pietro Jeng.

A year ago, a new speech synthesis system called WaveNet was presented by Google’s DeepMind, an artificial intelligence company.  As its name suggests, WaveNet generates speech by using neural networks to predict what the sound wave of a sentence should look like.  I thought this was interesting because it’s such a counterintuitive way to produce speech sounds.

WaveNet in Action


In this … Read the rest

The Kinkiness of a Vibrating String

Here’s a super-slow-motion video of a vibrating violin string:

Video by Jost Fischer.

I think this is pretty cool — there’s this kink that’s travelling up and down the length of the string.  What’s going on here, and why don’t we see this with the naked eye?  In this post I’ll explain how a bowed string vibrates, and how, unintuitive as it seems, the odd kinky motion of the Read the rest

Why Inhaling Helium Makes You Sound Like a Chipmunk

Here’s a novel idea from the King’s College Choir:


In the video, one of the choristers gets help hitting a high note by taking a breath from a large helium balloon. (Obligatory warning: it’s dangerous to try this at home.)  So… does this actually work?  Does inhaling helium really make your voice higher?

In an earlier post, we looked at how the pitch of your voice depends on Read the rest

Digitally Transforming a Female Voice to a Male Voice

Here’s a recording of a woman reciting a line from the Catalan poem La Vaca Cega:

Speech-female.wav by xserra / CC BY.

Suppose that you wanted to take the recording and change the quality of the voice — change it into a male-sounding voice, for instance.  How would you go about it?  I did this recently for an online audio processing course I took, Read the rest

The Mechanical Talking Head: An Early Speech Synthesiser

Photo of the Euphonia
The Euphonia, a mechanical speech synthesiser. Public domain photo, sourced from Atlas Obscura.

In a dimly-lit room in the back of London’s Egyptian Hall, a few curious people had gathered.  Each had paid a shilling for the privilege of seeing the object standing in the centre of the room.  A grotesque device it was — the mask of a woman’s face, framed in the fashionable ringlets of the day, Read the rest

What Makes a Musical Sound Part 3 — Envelope and Playing Techniques

What, would you say, is the main difference between a piano note and a flute note?  You might suggest that it has something to do with the shape of the note — a piano note is struck once and then simply held down, while a flute player has to actively blow throughout the duration of the note.

In part 2 of this series on what makes a musical sound, we Read the rest

The Fourier Transform and the Spectrum

Sine waves combining to form a violin waveform.

In What Makes a Musical Sound Part 2, I talked about the spectrum, which shows what frequencies are present in a sound.  In this explicative post, I’ll go into more detail about how we obtain the spectrum, and about what it means when we say a sound is made up of different frequencies.

Sine Waves

But first – what does Read the rest

What Makes a Musical Sound Part 2 – Tone Quality and Spectra

Here’s a violin playing the note G (with frequency 784 Hz), followed by a flute playing the same note:

Sounds from the Philharmonia Orchestra’s free sound samples / CC BY-SA 3.0.

In part 1 of this series on what makes a musical sound, we looked at two basic properties of a musical note – its pitch and loudness. Since these two notes … Read the rest

What Makes a Musical Sound Part 1 – Pitch and Loudness

In a previous post we saw that sound is made up of waves of differing pressure in the air, caused by the vibration of air particles. Musical sounds are no exception – even the most intricate and exquisite chords are still encoded in the back-and-forth motion of the air particles that carry the wave from source to ear. What is it that makes some vibrations sound musical, while others sound … Read the rest