Tag Archives: frequency

Happy Birthday Heinrich

If you are a guitarist then today is the day joyously to play D# – string 4, fret 1. The reason to celebrate the 155th birthday of Heinrich Rudolph Hertz (1857-94), the man after whom the calibration of pitch frequency is named. That D# (the one below Middle C)  is the nearest note to 155 Hz.

1 Hz = 1 cycle per second – that is to say that the D# in question makes the air vibrate 155 times per second.

Orchestras in the west tune to A  = 440 Hz, with the exception of the French who prefer 444 Hz.

But the situation has not always been stable. Harpsichords in the Baroque were tuned to A = 415 Hz; some organs were tuned to A = 465 Hz. The French preferred 398 Hz.

Human hearing range is 20 Hz to 20,000 Hz (20 kHz).

The range of a piano is 27.5 Hz (no point in going much lower) to 4186 Hz (we could perceive notes which are much higher than this, but would we enjoy them?)

Octave Displacement

Most people – even those with no formal musical education – are familiar with the term octave, even although they might struggle to define it. This short series of facts might do:

  • each note makes the air vibrate at a given speed (frequency) e.g. 440 cycles per second or 440 Hertz (HZ)

  • the ear judges pitch by an awareness of the speed of these vibrations

  • if the frequency of a note doubles – the pitch goes up an octave (8ve)

  • if the frequency of a note halves – the pitch goes down by an 8ve

  • this relationship of half/double makes notes fit so well together that upon hearing them simultaneously, many listeners perceive only one note

  • for this reason the notes share the same alphabetical name

  • moving some of the notes of a melody into a neighbouring 8ve is called 8ve displacement and many composers use it to conjure a sense of strangeness while retaining a sense of the familiar

Octave displacement can seem nearly as odd for the performer as the listener. For most people, it would be easier to do this by reading or memorizing rather than improvising and most would agree that it would be easier on an instrument than with the voice. That’s why this seems so amazing – particularly from 0:29 [kml_flashembed movie="http://www.youtube.com/v/JlJvOCG22aU" width="425" height="350" wmode="transparent" /]

The Perfect Instrument

What constitutes the perfect voice? Is it totally subjective or can the ingredients be isolated and described objectively?

According to research carried out on behalf of Post Office Telecom it is possible to be very precise about this. Perhaps not surprisingly, the research was carried by two people who can count music among the many strings on their bows:

  • Andrew Linn – lecturer in linguistics and phonetics at Sheffield University, and accomplished organist
  • Shannon Harris -sound engineer and keyboard player with, among others, Lily Allen and Rod Stewart.

Shannon Harris, speaking to James Naughtie on Radio 4’s Today described the research procedure. Fifty unknown voices were played to participants and the common traits of favoured voices noted:

  1. good bass frequency response – between 35.5Hz and 12.2 KHz
  2. a delivery speed 160 words per minute – with a gap of 0.5 sec between phrases
  3. an intonation contour which goes downwards! (take note, fans of AQI/HRT – no not that one, the other one*)

This information proved sufficient to synthesise the perfect male and female voice, both of which can be heard here.

Presumably to give these findings some popular meaning, well known voices featuring some or all of these were listed. They included:

  • Judi Dench
  • Michael Gambon
  • Mariella Frostrup
  • Alan Rickman
  • Jeremy Irons

You’ll note the complete absence of national/regional accents and also of context. Would dozens of orators using RP or SBS be suitable in the Scottish Parliament or Welsh Assembly? Would Alan Rickman make a convincing drill sergeant? Could Juni Dench comfortably MC a Hip-Hop festival?

James Naughtie asserted – correctly in my view – that what people were looking for was a voice, reading with understanding and meaning. In the context of teaching, an individual teacher’s delivery would surely change depending on where in the 3-18 continuum they were placed.

It seems clear that the voice was being regarded as an de-contextualised instrument. No composer would cite any single instrument as the perfect one without knowing the setting and the emotional intention. The harpsichord is not a great instrument for marching to war and bagpipes are rarely booked for dinner jazz.

*Stephen Fry consigned Australian Questioning Intonation aka High Rising Terminal to Room 101 on BBC 2. Interestingly the researchers report that this sound suggests a lack of confidence. Viewed thus, it is not surprising that is is mainly the domain of teenagers for whom fitting in and confidence are big issues. Contrastingly, David Crystal, a prolific writer on language, considers that AQI is favoured by young people as it sounds inviting and inclusive and because, generally, young people are more interested in meeting new people and making new friends than older people whose family and social networks are perhaps happily in place.