5070- Exam 1

What are some benefits of using acoustic measures in clinical practice?

Objective data, track progress, reduce listener bias, enable EBP, provide client biofeedback

Why is it important for SLPs to understand acoustics?

Helps interpret client issues, apply EBP, and use technology effectively in therapy.

What are 4 characteristics of science?

Empirical, deterministic, predictive, parsimonious.

How does sound travel through air?

Via compression and rarefaction of air molecules in longitudinal waves.

What’s the difference between simple and complex sound waves?

Simple = single frequency (pure tone); Complex = multiple frequencies.

What’s the difference between transverse and longitudinal waves?

Transverse: particles move perpendicular to wave direction; Longitudinal: parallel.

What’s the human hearing range in Hz?

20 Hz to 20,000 Hz

How do you calculate period from frequency?

Period = 1 / frequency

How do you calculate wavelength?

Wavelength = speed of sound / frequency

What is phase and how is it measured?

A point in a wave cycle, measured in degrees (°).

What happens when two sounds are 180° out of phase?

Destructive interference → cancellation (silence)

What is a harmonic?

An integer multiple of the fundamental frequency.

What are the four types of sound patterns?

Periodic, nearly periodic, aperiodic, harmonic

What is natural resonant frequency?

The frequency at which an object vibrates most efficiently.

What are aural beats?

Beats caused by two nearby frequencies interfering (e.g., 440 Hz + 442 Hz = 2 Hz beat).

What is damping?

The reduction of amplitude when a sound doesn’t match a system’s natural frequency.

What is intensity?

The amount of sound energy (power); related to amplitude; measured in decibels (dB).

How does sound pressure relate to loudness?

Greater pressure = greater intensity = louder perceived sound.

What’s the difference between linear and logarithmic scales?

Linear = equal steps; Logarithmic = multiplicative steps (better for hearing range).

What’s the formula to calculate dB SPL?

dB SPL = 20 × log10(measured pressure / reference pressure).

What happens when two identical sounds are combined?

+6 dB increase due to pressure doubling.

What do dB SPL, dB HL, and dB SL stand for?

Sound Pressure Level, Hearing Level, Sensation Level.

What is dBA weighting?

A filter that mimics human hearing sensitivity (de-emphasizes low frequencies).

What is loudness?

The perceptual correlate of intensity; subjective.

What does RMS stand for and what does it do?

Root Mean Square; calculates average sound amplitude over time.

What are features of loud speech?

Increased subglottal pressure, vocal fold movement, articulator movement, and consonant bursts.

What does the inverse square law say about sound?

Sound intensity drops by 1/4 when distance doubles.

What is a Voice Range Profile (VRP)?

A plot of dB SPL across frequency to visualize vocal range and intensity.

What is the Mel scale?

A pitch scale where 1000 Hz at 40 dB = 1000 mels; reflects perceptual pitch.

What is a semitone in frequency?

1/12 of an octave; approx. 5.9% increase in frequency.

What is the frequency difference limen (DL)?

The smallest detectable change in frequency.

What is the missing fundamental phenomenon?

Pitch is perceived even if the fundamental frequency is missing, based on harmonics.

How does sound travel through the auditory system?

TM → Ossicles → Oval window → Cochlea → Basilar membrane.

What frequency does the ear canal naturally amplify?

Around 3000 Hz.

Why does sound get amplified from TM to oval window?

Surface area difference increases pressure; ossicles provide a lever boost.

What does tonotopic organization mean?

Different parts of the cochlea respond to different frequencies (base = high, apex = low).