Piano Sound: From Sound Ideal to Detailed Sound

A piano sound is more than just string vibration: For a digital piano to sound lively and authentic, it must also reproduce the many dynamic details of sound, such as string and damper resonance, and even mechanical background noise.

Piano Sound with Background Noise?

Whether you play an acoustic or digital piano, you want a full, rich sound. Moreover, you probably prefer your piano sound without annoying background noises such as a squeaky sustain pedal or a rattling key. On the other hand, few would mind the noises made by the keyboard, pedals, and hammer action of a real piano.

In fact, the mechanical noise of pianos and grand pianos is not only part of their sound but also louder than many would expect. When you play a muted hybrid piano, all the background noises become isolated and hence audible: the damper mechanism, the fall-back of the hammers, and, last but not least, the keyboard. Even though some of these sounds are quite subtle, they still make up a part of the overall sound you hear when you play and listen.

A piano sound that thrives on ambient noise is particularly popular in neoclassical piano music (Felt Piano). Very atmospheric piano sounds, preferably an upright piano, are also often used in movie scores. When recording, the microphones are placed as close as possible to the action of the piano to record this “background noise” as vividly as possible. This gives the recording closeness and intimacy.

Piano Sound Is Unique!

Even when a piano is tuned as uniformly as possible, each note or range of notes has its nuances: some notes have a dull resonance, others a slight click in the action. Or you may hear the felt crumple slightly under the hammers. This is all perfectly normal within certain limits, and can even be part of the charm of an older piano where certain nuances of sound have developed over the years.

Do All Digital Pianos Sound the Same?

This is not the case with digital pianos, because in principle all digital piano models are identical – the beauty of digital technology lies in its precision. The piano sounds in a digital piano are technically optimized to sound equally good and balanced everywhere.

Why Edit Digital Piano Sounds?

Despite digital sound generation, the sounds of identical digital piano models can vary. There are two reasons for this:

1. The digital piano sound is unbalanced due to problematic room acoustics.
2. The piano sound has been intentionally altered, similar to the intonation of an acoustic piano.

In both cases, the sound editing options are a great advantage. Editing functions such as Virtual Technician (Kawai), Piano Designer (Roland), and Piano Room (Yamaha Smart Pianist) are useful in two ways:

1. They allow you to consciously change certain sound details to give the playing and sound characteristics an individual touch.
2. You can alter the piano sound of a digital piano to match the acoustic room conditions.

Point 1 is interesting for those wanting to get creative with sound design. Virtually voicing the sound of your piano according to your own musical and aesthetic ideas is mainly for advanced pianists. However, is also an interesting way for beginners to learn more about the details making up the piano sound. The Virtual Technician (Kawai) and Smart Pianist (Yamaha) piano apps explain this clearly.

Point 2 is very special because the intonation of each note requires experience in piano construction and acoustics. You need to know how to acoustically assess the room in which the digital piano is located to adjust individual notes if necessary. Naturally, not all digital pianos support this feature, which is usually reserved for higher-end instruments. If available, you can use the Single Note parameters to adjust the volume and tone of individual notes. This is for example useful when individual notes cannot reach their full potential due to room resonance.

Key-Off Effect and Fallback Noise

The simplest piano sound would be a recording of a note being struck. However, in order to reproduce authentic playing behavior, you must take into account the state of the entire instrument. For example, a piano sound will not simply stop vibrating when you release a key. If you listen carefully, you will hear some resonance in the decay. There are several factors involved:

• Slight resonance when playing with damper pedal (inertia of a piano string)
• Overtone resonance of undamped strings (aliquot)
• Duplex scale resonance

This resonance is highly dependent on the way you play and sounds very different on a loud staccato than on a slowly released note. With the latter, you can hear the damper gently striking the string. While the keystroke during the decay can influence these overtones, the release of the key also brings the fall-back noise of the hammers. Of course, this action also takes place when playing with sustain pedal, but of course without the damper. However, the fall-back noise can now create resonances in the undamped strings.

Regarding String Resonance

This aspect also enriches the sound of pianos and grand pianos in a very complex way. The string resonance always depends on which notes are being played and damped. As a constant interplay of overtones, it makes the overall sound into what we love and appreciate as a vibrant and beautiful piano sound. It is virtually impossible to recreate these complex relationships using samples alone, which is why many electronically generated sounds use a mixture of multisampling and physical modeling.

With digital pianos, a distinction is made between damper resonance and sympathetic resonance. With many piano models, you can individually adjust the degree to which these resonances affect the sound.