Changes in Speed and Pitch, and Multi-noted Series

Now that we’ve looked at the five basic pitch patterns and the four basic song patterns, let’s explore a couple of ways to extend and combine the vocabulary we’ve learned.

Changes in speed

One of the basic questions we ask of any bird sound is, “are the notes slow enough to count, or too fast to count”?  Sometimes, the answer is both.

Some bird sounds change in speed. If the elements in a series are more closely spaced on the spectrogram as you move from left to right, then they are growing more closely spaced in time, which means that the series accelerates. If the elements grow farther apart, the series decelerates.

Here are a couple of examples. The song of the Wrentit is a series of notes that accelerates into a trill, while the drum of a Yellow-bellied Sapsucker starts as a trill of tapping notes, and slows into a series.

Changes in pitch

Phrases, series, warbles, and trills can also change in pitch. For example, a warble might sound upslurred if it shows an overall trend towards higher notes. Similarly, a series might fall in pitch if each note starts slightly lower than the last, even though each individual note may be upslurred.


Overslurred series are quite common among bird sounds. Here are two examples:

Changes in both speed and pitch

Many sounds change in speed and pitch at the same time. A quick glance at the spectrogram of the Sora’s whinny shows us that it’s an overslurred, decelerating series with an early peak:


Here’s a decelerating, downslurred series of upslurred whistles:

And here’s a phrase accelerating into an upslurred warble:

Multi-noted Series

Sometimes the repeated elements in a series may themselves consist of multiple notes. A two-noted series sounds like a two-syllabled word repeated, such as “peter peter peter;” a three-noted series, like a three-syllable word repeated, such as “teakettle teakettle teakettle.”

Examples of two-noted series

Examples of three-noted series

Yes, there are four-noted series too

With the basic vocabulary that I’ve introduced in these three posts, we can describe the pattern of almost any bird sound.  But there’s more to bird sounds than just pattern.  Stay tuned for the next installment in the series.

3 comments to Changes in Speed and Pitch, and Multi-noted Series

  • Peter Boesman

    Hi Nathan,

    I am a bit surprised you also use the terms ‘upslurred’ and ‘downslurred’ for song patterns.
    In these cases I would rather use ‘rising’ and ‘falling’.

    I have always understood a slur is a continuous sound without any articulation in between (no stopping and starting, no short moments of silence in between), but a continuous sound that obviously can change in pitch and tonality.

    E.g. a rising series of downslurred whistles.
    (rather than ‘an upslurred series of downslurred whistles’ which reads a bit awkward in my opinion)

    For ‘overslurred’ I obviously use ‘first rising, then falling’.
    You need a few more words, but then you can also add more information,
    e.g. a long trill, rising gradually, and falling at the end.

    Any reason why you avoid ‘rising/falling’ for song patterns?
    Or just a matter of choice?

    Greetings,
    Peter Boesman

  • Nathan Pieplow

    Hi Peter,

    Excellent points. I had not thought much about the connotation of “slur” as a single note, but I can see your point of view. I had already come to the conclusion that “rising” and “falling” work well as synonyms of “upslurred” and “downslurred”. I have no problem with constructions like “a rising series of downslurred whistles”, but neither does it bother me to use “upslurred” to refer to a series.

    I think the main reason I went with all the “-slur” words was because “overslur” and “underslur” only make sense in that context. And I did feel it important to have a single word for “overslur,” because the pattern is so very common in bird sounds (both in individual notes and in series). In writing my field guide, in which space is at a premium, I’ve found that “rising, then falling” is simply not efficient enough. I spent quite a bit of time trying to devise the best way of saying this, and I ended up settling on “overslur”. At the time, several years ago, I was more likely to coin a new term when I needed one. Now, I’m much more concerned with making my terminology accessible. But I’ve kept “overslur” due to what I see as its tremendous utility.

    Overall, I’m eager to see the birding community begin to adopt a more standardized vocabulary for describing sounds (whether it’s my vocabulary or not, though I do think my vocabulary has advantages over any other system I’ve seen).

    In a nutshell, that’s my reasoning.

  • Peter Boesman

    Hi Nathan,

    Thanks for the feedback !

    You could of course also use ‘rising/falling series’ which is almost equal in length than ‘overslurred series’. Also ‘rising’ and ‘falling’ are short words. It is a matter of choice…

    Ascending/descending is an equally good alternative, and it is quite consistent with ‘crescendo/decrescendo’, but these words are even longer…

    I fully agree to aim for standardized vocabulary !!
    I will try out your proposal for some time and let you know any issues (especially the tone qualities I am curious about).

    What I have read sofar looks good!
    One other remark maybe:
    Intuitively I associate a ‘trill’ with something that sounds like ‘trrrrrr’, which (like in music) is a fast alteration between two notes.
    The example of the sparrow I would have described myself as a ‘fast series’, or when it really is nolonger countable, a ‘rattle’, which is rather a quick succession of single notes.

    Let me know your comments !

    Greetings,
    Peter