Overtone vs. Undertone

Attribute	Overtone	Undertone
Definition	Higher-frequency component of a sound	Lower-frequency component of a sound
Perception	Usually heard as a harmonic of the fundamental frequency	Usually heard as a subharmonic of the fundamental frequency
Strength	Can be stronger or weaker than the fundamental frequency	Typically weaker than the fundamental frequency
Creation	Generated by the vibration of smaller divisions of a vibrating object	Generated by the vibration of larger divisions of a vibrating object
Harmonics	Can have multiple overtone harmonics	Does not have multiple undertone harmonics
Frequency	Higher frequency than the fundamental frequency	Lower frequency than the fundamental frequency

Introduction

When it comes to discussing the attributes of sound, two terms that often come up are overtone and undertone. These terms are used to describe different aspects of the harmonic structure of a sound. While they may seem similar, there are distinct differences between overtone and undertone. In this article, we will explore these attributes in detail and understand how they contribute to the overall perception of sound.

Overtone

Overtone refers to the higher frequency components that accompany the fundamental frequency of a sound. These additional frequencies are integer multiples of the fundamental frequency and are responsible for the timbre or tone color of a sound. Overtone series can be found in various musical instruments, including strings, wind instruments, and even the human voice.

One of the key attributes of overtones is their harmonic relationship with the fundamental frequency. For example, if the fundamental frequency of a sound is 100 Hz, the first overtone would be at 200 Hz, the second overtone at 300 Hz, and so on. This harmonic relationship creates a sense of consonance and stability in the sound.

Another important attribute of overtones is their relative amplitude or strength. In most cases, the amplitude of the overtones decreases as their frequency increases. This amplitude distribution contributes to the unique timbre of different instruments and voices. For example, a violin produces a rich and complex sound due to the presence of strong and well-defined overtones.

Furthermore, overtones play a crucial role in the perception of pitch. While the fundamental frequency determines the perceived pitch of a sound, the presence and distribution of overtones contribute to the perceived quality and richness of the sound. This is why two instruments playing the same note can sound different due to variations in their overtone structure.

In summary, overtones are higher frequency components that accompany the fundamental frequency of a sound. They have a harmonic relationship with the fundamental frequency, contribute to the timbre of a sound, and play a role in the perception of pitch.

Undertone

Unlike overtones, undertones refer to the lower frequency components that accompany the fundamental frequency of a sound. While undertones are less commonly discussed compared to overtones, they still play a role in the overall harmonic structure of a sound.

One of the key attributes of undertones is their relationship with the fundamental frequency. Unlike overtones, undertones are not integer multiples of the fundamental frequency. Instead, they are subharmonics or fractions of the fundamental frequency. For example, if the fundamental frequency is 100 Hz, the first undertone would be at 50 Hz, the second undertone at 33.3 Hz, and so on.

Undertones are often associated with the perception of a deep and rich sound. They can be found in certain musical instruments, such as bells and gongs, where the vibrating body produces both the fundamental frequency and its subharmonics. However, it is important to note that undertones are not as prevalent or easily distinguishable as overtones in most sounds.

While overtones contribute to the timbre and pitch perception of a sound, undertones are more subtle and can add a sense of depth and complexity to the overall sound. They can create a sense of resonance and richness, especially in low-frequency sounds.

In summary, undertones are the lower frequency components that accompany the fundamental frequency of a sound. They are subharmonics and contribute to the depth and richness of the sound, although they are less prevalent and distinguishable compared to overtones.

Comparison

Now that we have explored the attributes of both overtones and undertones, let's compare them to understand their similarities and differences.

Harmonic Relationship

Both overtones and undertones have a relationship with the fundamental frequency of a sound. However, overtones are integer multiples of the fundamental frequency, while undertones are subharmonics or fractions of the fundamental frequency. This distinction in their harmonic relationship contributes to their unique characteristics and perception.

Amplitude Distribution

Another aspect to consider is the amplitude distribution of overtones and undertones. In most cases, the amplitude of overtones decreases as their frequency increases. This gradual decrease in amplitude contributes to the timbre and richness of the sound. On the other hand, undertones are generally less prevalent and have lower amplitudes compared to overtones. They add a subtle depth to the sound without overpowering the fundamental frequency.

Perception of Pitch

Both overtones and undertones play a role in the perception of pitch. The fundamental frequency determines the perceived pitch of a sound, while the presence and distribution of overtones contribute to the perceived quality and richness of the sound. Undertones, although less distinguishable, can add a sense of depth and resonance to the overall perception of pitch.

Instrument and Voice Characteristics

Both overtones and undertones contribute to the unique characteristics of different musical instruments and voices. The presence and distribution of overtones create the distinct timbre or tone color of an instrument or voice. For example, a piano and a guitar playing the same note will sound different due to variations in their overtone structure. Undertones, although less prevalent, can add a sense of depth and richness, especially in low-frequency sounds.

Overall Contribution

While overtones are more commonly discussed and have a more significant impact on the perception of sound, undertones add a subtle complexity and depth to the overall harmonic structure. Overtones are responsible for the timbre, richness, and pitch perception of a sound, while undertones contribute to the sense of resonance and depth.

Conclusion

In conclusion, overtones and undertones are two attributes of sound that contribute to the overall perception and quality of a sound. Overtones are higher frequency components that accompany the fundamental frequency, while undertones are lower frequency components. They have different harmonic relationships, amplitude distributions, and contribute to the timbre, pitch perception, and overall characteristics of different musical instruments and voices. Understanding these attributes helps us appreciate the complexity and richness of the sounds we encounter in our daily lives.