Time for some Fun Facts.
Have you ever wondered why people's voices from the 1900s sound very different to ours. It sounds rapsy with high nasal cadence. Moreover, almost all of them sound the same.
Join me on a roller-coaster thread https://twitter.com/isasquare/status/1239085491141718016

First off. Let's all understand and recognise the voice we're talking about. Here is a typical example of the voice in question. And I'll be adding similar recordings from various people along this thread.

So why do they all sound like that? Well, there are two reasons for that. I will begin with the simple one.
You see, the earliest recording set is called Wax Cylinder player. Invented by... guess who?... Well, Thomas Edison, the light-bulb guy. Sometime in late 1800s

Here is a music from a Wax Cylinder, that was recorded just 2 years after the sinking of the Titanic!! That's over 100 years old!. Let that sink in.
You know what's interesting? The Wax Cylinders have absolutely NO electronics. It's purely analogue, doesn't need electricity.

Later inventions brought us Strip recorders, Photoelectric and then the Magnetic recorders (precursor to 'modern' tape recorders). These were the recordings available in the 1900s. So why am I mentioning all this?

The reason is because those technologies cannot record low frequency very well, some not at all. So the voice recordings are clear in midrange and high, but the lower frequencies are canceled out. Unlike today where we have control in the whole audible range (20Hz to 20KHz)

So that's the first explanation. There is also another reason, which is less technological and more Societal.
It is the amalgamation of accents known as the 'Mid-atlantic or Transatlantic accent". This is an accent that was cultivated by blending British and American accent.

It became sort of a neutral accent and very prestigious, it was used in schools, speeches, cinema etc. Although it declined after the World War II, many places still held onto it, especially colonial times and places. So, even if we ignore the limitations from recordings....

Speeches Tafawa Balewa to Sardauna to Azikiwe to Awolowo. We'll notice they all have similar accent and this is perhaps by virtue of this Transatlantic accent.

I will leave you to guess whose voice this is:

Another final thing I want to add is the evolution of voice.
There has been many studies documenting the change in human voices. Primarily as a result of changes in society. One of the most significant is the change in Female voice.

The average voice of women today, is different from that of our grandmothers or great grandmothers. This is primarily due to the changes in social structures that happened in 20th century. As women occupy positions of power and dominance, their voices also change.

There is 'cause & causality paradox' at play here; Do they change their voices so they can enforce the dominance, or did their voices change when they occupy the said positions of power.
It's hard to say and you'll find arguments on both sides of the aisle.

One prominent example is former UK prime minister, Margaret Thatcher
Thatcher employed a speech professional to help tune her voice to make her sound more authoritative. As a result, she deliberately dropped the pitch of her voice by a staggering 60 Hz!!! (this is huge).

I've also thought about this for a while now (I might be wrong). The voice of President Buhari has significantly changed pre 2015 and now.
While it is hard to say if this is due to aging, I feel the dominance phenomenon is also at play. Maybe I will run a research on him.

Perhaps I'll gather PMB's voice before presidency and his voice now (if I can find them, no malice intended). And then run some frequency analysis and see if/how it has changed.

Another hypothesis I have is SLS. His voice has significantly changed pre-Emire and post-Emir. I might be mistaken, but it's definitely worth analysing. I feel he's plunged some frequencies on the high-pitch. It's also interesting since he's in his 50s- when voices barely change.

Without having those studies, we can't say for sure.
I will end the thread here and hope u enjoyed it.
In case you're new to the fun fact series, then check previous threads quoted on each other here. https://twitter.com/isasquare/status/1239085491141718016?s=19